The sprites aren't in rk9, at least; the sprites (shown above) were from a separate thing for the stream and we didnt' see all of them.Which basically means it was actually GameFreaks accidentally giving R9K stuff they had no business having.
Eh, to be fair, stuff like that happens. After all, dataminers already had found leftover data in SwSh itself.
What gets me curious is the presence of the (from what I understood) full 1k+ pokemon sprites.
I was actually assuming that in its final form (aka once all DLCs are released) SV will have every pokemon available. One more reason to believe so.
(After all, if we now account for SwSh, BDSP, Let's Go and SV, I think there's like, less than 50 pokemon left that don't have a "updated model" I believe?)
I doubt this is proof of anything akin to "EVERY pokemon is here!!" by the end of SV's life (I think we'll get ~+200 and that's about it). This seems to be the "standard" style they want to use for box sprites (BDSP already made the first 4 generations anyway) now, so I imagine these also get applied to Home; we already know the battle data will have them. There being other options to view all Pokemon in some fashion, separate from the render style they currently use, would make sense.