Ehh, I feel like people are blowing him out of proportion. Pikachu is already small and light and his hitboxes are pretty decent for his size, but Pichu is even smaller and lighter and his limbs just aren't as long as Pika. This will automatically make him way worse than Pikachu because it means that his neutral will be much worse than Pika's and he will even have a hard time getting in unless he is way faster than Pika (which he isn't). Unless he has some crazy punish game or broken move, his weight combined with lack of range and dealing damage to himself will probably make him bad no matter how good Pikachu is in this game.
EDIT: on another note I think a lot of top players are really sleeping on Meta Knight right now due to him not having ladder anymore and also him not being drastically changed from sm4sh. He is still consistently making it into "seems pretty good" tier in a lot of people's tier lists but the main thing I think will push him really hard once the game comes out is his "meta niche". He will have an undeniably good matchup against anyone who has a bad recovery or is slow/bad/floaty in the air and I think this will be HUGE for him. Smash 4's engine sucked for a character like Meta Knight who thrived on having a good recovery and being able to gimp people, the only reason he was high tier was ladder combo. Smash Ultimate is way better for Meta Knight as a character due to lack of air dodge spam and worse recoveries. Some of his worst matchups from sm4sh like cloud and mario are now probably much better for him. If Characters like Marth, Roy, Fox, Belmonts, Mario, Cloud, and Ike all end up being as good as people are saying they are, you can bet that Meta Knight will crawl up the ranks as a counter to these character's mediocre off stage games/linear recoveries. Keep in mind his most buffed arial was Dair which is also by far his best for gimping.