Here is another page from the Tomy Toy preview catalog for 2018 releases. These are their intended 8 inch plush dolls. It's not exactly a prototype, & the Amy's already been seen, so it's pretty safe to say this is what the dolls will look like.
Sonic has 1 hand in a fist, the other with a pointing finger & so does Eggman. Eggman's kind of short/stumpy & has a really big mustache for some reason. He's not extremely on model, but looks fairly ok. Amy's been covered above. Somehow classic Super Sonic sneaks into the all modern line-up here and.....he doesn't look that great. With tiny hands in fists, a bit of 'big body' going on, what really gets him is the way too small, pointy eyes & almost shrivelled small spikes that don't look to be standing up much at all. SS's signature feature is being yellow & having 'up' spikes that are quite different. Vector's next and, while he's not as good as GE Entertainment's he does seem to have all his details like glove cuffs, shoes, & chain. He's posed with a 'thumbs up' just like Amy.
A Neutral Chao is always nice to have, & this one looks good here. It has the yellow tips for the limbs & a good fade on the head. It seems like a real solid effort.

If these are priced right, they should do pretty well. The strongest offering here being the Chao because those are scarce but wanted, and the effort is really good. The weakest is by far Super Sonic who looks goofy & wrong. Amy's poor ears & Eggman's odd proportions do a little to hold them back, but it's nothing terrible if they're not horribly costly.

In the gallary is another photo for Tomy's upcoming plushes in 2018. They're all from the line of "Pose Plush" except the Knuckles, who belongs with their classic line. Notice how each of the 'pose' characters has arms that are 'doing something'.
The Shadow has one open hand and one fist, also one elbow is bent & he's clearly looking off to one side. 

The Tails has both elbows bent, and one arm is naturally raised. Silver is perhaps the most dynamic out of everyone here, and is actually quite interesting. They've actually got him gesturing with his psychic palms as he does in the game. The chest fur piece is actually large too, and dimensional. His expression is rather aggrivated, though.
The classic Knuckles is their weakest offering, look at his tiny, flat fists. There's even an un-quality thin lame folded-over thumb there too. He's odd to see, because the 'pose plush' do such a good job in this case, but they completely under-value his...well...the feature he's named for: Big fists & knuckles.
These Pose Plushes could be one of Tomy's best Sonic plush efforts so far. Shadow's spikes look good, his head shape is right, all his details are there, the Tails is pretty cute, & the Silver is actually pretty darn super. If it lives up to the photos, these may be on a fan's list of "do buy!"