Normally "everything you need to know" is a wild exaggeration but this one's actually pretty good and highlights most of the important caveats regarding the initial service.
Firstly, amazingly, the railway's not quite finished. Opening on 24 May is still "subject to final safety approvals", which may be a shoo-in but does suggest the line couldn't have opened this week even if TfL had wanted it to because there's still outstanding project assurance to complete.
We learn that Monday 23rd May is the day the TfL Rail brand is finally extinguished, seven years after it began in May 2015. This means Romford, Southall and Taplow will all be getting purple overhauls even though trains from those stations will continue to follow exactly the same routes as they do now.
'Nine new stations' opening is a proper gamechanger, depending on your definition of 'new stations'. Technically the only new station in a new location is Woolwich - and maybe Canary Wharf - the others are all bolt-ons to existing stations.
There's also confirmation that Bond Street will not be opening along with the rest of the line - news first revealed in January. Opening 'later in 2022' is impressively vague, as it currently has to be, and could mean up to 221 days of trains passing straight through.
Initially we're only getting one train every five minutes, which is good but not as good as, say, existing frequencies on the Jubilee line. The central section won't be offering "up to 24 trains an hour" until this time next year.
It's somewhat embarrassing to have to launch the service with restricted hours and no trains on Sundays. Not starting until 6.30am and closing down around 11pm is going to thwart a few commutes, and the absence of trains between Saturday evening and Monday morning won't be popular. It's all so that staff can continue to practice future routing patterns without passengers on board, and because somehow the software that's been playing up for years still isn't 100% perfect. Only when services mesh seamlessly will travel on Sundays become possible, however long that takes.
There will however be a Sunday service on Platinum Jubilee weekend because it wouldn't do to deny service on a line named after the Queen, but that'll only be from 8am to 10pm... and heavens they're making this complicated.
TfL are also keen to remind everyone that services will initially operate as three separate railways. They first mentioned this in a press release in 2017, but most Londoners are still going to be surprised that the new purple line has two disconnects.
They've tried to make this clear in the line diagram that'll be posted up in Crossrail carriages.
Helpfully they've provided a link to a pdf. Here's the central bit (click to see the whole thing).
The three lines are each shown separately, but joined at Paddington and Liverpool Street with 'walking man' connectors. I don't remember seeing one of those on a line diagram before. At Paddington you'll need to ascend and find platforms 11, 12 or 14, and at Liverpool Street ascend and find platforms 15, 16 or 17. We've yet to discover quite how long those walks are, but the time taken won't be insignificant.
Note how Liverpool Street is shown as all one station but Paddington as two stations, because only the Bakerloo line connects with Crossrail's central section. This is different to the way Paddington is normally split, where the Bakerloo is coupled with the District and Circle lines instead... and what a diagrammatic can of worms we've opened.
If you're planning a through journey, expect to have to touch out on one level and back in on another. TfL's supporting text isn't entirely reassuring - all they say is that "daily and weekly price capping will apply" - but presumably the software will charge you for one journey rather than adding two separate fares.
At some point in the autumn - they haven't said when - the connecting tunnels at Paddington and Stratford will finally be opened. This will allow trains from Abbey Wood to run all the way through to Heathrow and Reading, but trains from Shenfield will go no further than Paddington. They explained all this last summer. The resulting service will look something like this...
...although this is my map and very much not TfL's.
Then finally in May next year the final timetable will be introduced and Shenfield to Heathrow will become a possibility. Basically have patience with what you're getting at the beginning, it should all be sorted within a year.
In almost excellent news, the new line will be nearly but not entirely accessible on the day it opens. Every station will be step-free except Ilford which still isn't finished due to construction issues. TfL are keen to pass the buck here, reminding us that "Network Rail expects to make that station step free in summer 2022."
Also only nine of the 10 central stations will have step-free access from street to train. At Abbey Wood it's only street to platform and you'll need to rely on staff with a ramp (but they'll always be available). Also Custom House only has level boarding if you're in the fifth (i.e. middle) carriage, not all along the train.
The Everything you need to know page doesn't quite include everything you need to know. It doesn't mention that trains will also connect to Moorgate station. It doesn't say that platform A is eastbound and platform B is westbound. It doesn't tell you which carriage to be in so you don't end up with a stupidly long walk at Whitechapel.
And for anyone hoping to catch the very first purple train on Day One there's no clue when precisely that'll be. No electronic timetable has emerged, Crossrail hasn't yet appeared within the Journey Planner, and the wildcard that trains will initially only run between 0630 and 2300 throws a proper spanner in the works.
You have just three weeks to get your head round all this before turning up to enjoy a ride. TfL must be hoping that as many people as possible read their Everything you need to know page, because otherwise the line's quirks are going to cause a fair amount of scratched heads, befuddlement and irritation. When Crossrail finally launches on Tuesday 24th May it's going to be brilliant but it won't be simple.