Grookey - aka 'Groovy Monkey'. I can see a few previous Grass-type Pokes in Grookey's appearance (Turtwig, Sewaddle, Rowlet) and for some odd reason the ears remind me of Cleffa. In terms of evolutions, I'm expecting some more musical terms in the names, but also I do like the idea that the final evolution would turn out to be a drumming gorilla, if only for being reminded of this advert from a while back (2007 apparently):
Cadbury gorilla advert
Grass/Rock and Grass/Steel both fit to me, but whilst I'd prefer Grass/Steel, I think it may well end up either Grass/Rock or even Grass/Ground (it could be using the stick as a way to feel vibrations through the ground or floor, I have heard of dancers with partial or full deafness being able to 'hear' the music through these vibrations). I can envisage this line doing well with Sound-based moves, and perhaps an Ability either along those lines (so boosting the power of Sound-based moves) or possibly more towards the stick side with maybe one that raises stats when using moves that affect the ground?
Scorbunny - its design reminds me of Torchic quite a bit actually. now whilst the 'Scor' part of its name could well be for 'Scorching', I'm going to take a punt and say that it's actually for 'Score' and the Scorbunny line will be football-themed. Following this line, the Fire/Electric premise seems a very plausible one - hear me out. The way I see it, the final evolution will be bipedal and designed to resemble a striker (plus one type of strike is a lightning strike, hence the Electric typing. It's tenuous I know, but it does make sense considering how powerful Electric-type attacks can be and the Pokes using them tend to be fast too, like lightning fast). Strikers are usually pretty agile and able to score with both their feet and their head, hence the yellow (Electric) tape close to Scorbunny's forehead. The final evolution I can also see having something that resembles 'studs' (like on football boots) on their feet. Perhaps a hare will be the animal inspiration here. Ability-wise, something like Iron Fist and Strong Jaw, but for kicking moves. The other route I can imagine for this line is that of a goalkeeper (maybe more of a middle evolution option) with the hands looking like they have gloves on, and an Ability similar to Magic Bounce?
Sobble is the intriguing one for me. Its name in some languages has the translation of being the Tear Pokémon, which makes me think of Cubchoo. They could potentially follow that and have it become Water/Ice (which would make sense if we also had Grass/Ground and Fire/Electric), but I'm not too sure there. Its design somewhat reminds me of Dewpider (with the 'bubble') and also Tympole too. I've seen some speculation that Sobble could become Water/Dragon via the Loch Ness Monster route, although I personally think Game Freak will save that idea for another Pokémon. Mostly though, Water/Ghost has been getting the love. It would probably be the most interesting route to take, but I honestly cannot come up with a final evolution based off of that that would make sense given the region (one idea was that Sobble will follow a theatre-style line, you know like with the 2 masks, one happy and one sad? That would be awesome but I can't imagine a design concept to go with that). In terms of an Ability, Protean would make sense if they go for an 'emotional' theme.