…. and has been for the last year.
After never having been available digitally, it’s been available since last June on The Criterion Channel, easily one of the top 5 streaming services (and some would say the very best) – some may still not know of it, or think it’s some niche thing, but it’s been around longer than Disney+, Paramount Plus, Peacock, HBO Max, etc - longer than pretty much any major streamer aside from Netflix, Hulu and Amazon (and many would say it has a better library than all of them.)
In any case, it’s there, along with the original 2001 commentary, and a behind-the-scenes on the Documentary Now! spoof (although without the actual full episode of the latter). Presumably the added bonuses were being saved for the new Blu-ray to entice people to buy the physical disc.
There are terrific apps out there that let you search across all streaming services to see whether something you’re looking for is streaming anywhere, or that let you compile a watchlist and be notified when something that’s currently unavailable pops up at a later date.