I was actually looking into this last night and yea they're missing a LOT of the previous furniture sets and the ones that are there, all had name changes and a lot of the furniture was altered and some pieces are missing now. Like it seems Cabana is now Rattan, but it's missing the little bookshelf and the screen! The screen would have looked great in this game! And the low table no longer has the glass middle. Classic Series is the Antique Set, which mostly looks the same, but the loveseat is gone completely. The Lovely Series seems to be replaced by the Cute Set...but that's a little bit of a stretch considering how different the items look, it just has the heart theme about it, but the pinks were dulled a lot. I think it's a pretty set, but it's vastly different from the Lovely Series. And I mean, none of the original Series of furniture is really in the game by name, just a bunch of stuff that seems it was more inspired by the originals. It's really bizarre they took that turn in the game. Out of the 37 furniture series we had in NL only 12ish sets really seem to even somewhat be in the game and that's a huge stretch because I was counting the Wooden Set you craft as a replacement for the Green and Blue Series and that's only because you can paint them blue or green.
Sorry that was a bit long, but I've been trying to see what's going on and I'm really sad so much OG furniture was just canned completely and what does seem to be in the game seems to be more from inspiration than those sets actually being back. I'm just really hoping stuff comes back in the form of updates.