With the new Generation of Pokémon, a new Anime comes along, one which seems to shatter the conventions of Pokéani even more than Sun & Moon did.

Now, that Ash and Gou are traveling the entire known Pokémon world, it's hard to say, which Pokémon Ash will catch, but assuming they're gonna be Gen 8 Pokémon, I think these (or at least their evolutionary lines) have a pretty good chance of joining him:

Sobble or Grookey
Corviknight
Impidimp
Centiscorch
Clobbopus
Flapple or Appletun

I know they are more than 5, but some, I just couldn't rule out. If I had to, I'd say Clobbopus, since it's evolution is so similar to Hawlucha, but I still think it got a good chance.

Now, for Team Rocket

James is definitely going to have a Hattrim, what with all the abuse it dishes out.

Jessie isn't as easy, I can see a couple working.
Nickit comes to mind first.
Or perhaps, SHE will own an Impidimp.
Or, since she has stated to love Poison types, maybe a Toxel, though I have a suspicionthat Toxel or Toxtricity is going to be owned by an Anime-Only, Alain-type rival.

What do you think?

team rocket won't get a pokemon, they'll use the gacha thing to get random pokemon in each episode they'll shown up

7077110
Dammit

Or, since she has stated to love Poison types, maybe a Toxel,

No, I think James would own a Toxel; you know how all his Pokemon tend to show intense affection for him (namely Cacnea, Carnivine and Mareanie)? I bet Toxel would be like that, especially if James was holding its egg and it hatched in his hands. That would cause it to think James is its mama, and therefore it would snuggle up to him like Mothim to a flame. And when Toxel evolves into Toxtricity, it would outright go rogue and do whatever it wants to its opponents regardless of James's commands.

7077171
All of them also tend to massively abuse him, which is why I thought Hattrim would be perfect.

7077472
I think the abuse is accidental (except for Mareanie), because they probably just like James so much that they don't realize they're hurting him. Hattrem only dishes out abuse because of loud noise, as seen in the Pokedex entry. If anything, Hattrem would abuse Jessie. And Wobbuffet as well. "WOBBUFF--*gets punched*" A fitting punishment for a punching bag wannabe.