Satisfactory Announcement

There’s a toilet in the living quarters. I don’t believe it flushes. Yet.

Is this just a cheeky way to announce the 1.0 date,

Pretty much, if you pause near the end and look in the lower right-side corner, it mentions it.

"Add toilet flushing to the game" has been an inside joke in the community for a while. Before that, it was "Add golf to the game." So, yeah, it's a cheeky way to announce 1.0. Does come off as weird to those not in on the joke.

There's a bunk room in the HUB, it's where you respawn if you die. There's a toilet modeled in a little booth in one corner, and it doesn't flush. This became a running joke in the community, the community managers would joke about $10 toilet flush DLC and so forth. So it's just perfect trolling to announce they're adding toilet flushing to the game (and also the full feature release of the game/end of early access at that time as well).