Maybe, but I doubt it, that's why the developers deliberately gave Ash a Pokemon Sword concert tour.
Here are the reasons:
1. Zacian - in the forest he chose him as the sword hero from Galar, in the fourth episode of Sword & Shield Arc, Ash has just picked up the sword.
2. Bea - they chose this person instead of Allister as if Ash chose the Pokemon Sword tour.
3. Pokedex about Dracovish in Pokemon Sword: Powerful legs and jaws made it the apex predator of its time. Its own overhunting of its prey was what drove it to extinction. (However, It wasn't Ash's pokedex talking about it, but Cara Liss mentioned it).
4. Pokedex about Sirfetch'd in Pokemon Sword: Only Farfetch’d that have survived many battles can attain this evolution. (Pokedex sounded the same in the episode where he fought Gallade).
Perhaps Allister will show up, but I doubt there will be a fight. It will probably be the same as in Unova, Ash was supposed to go to the dragon village but Iris did not recommend him, instead he chose the leader of the poison type gym, despite this he met Drayden anyway, but without the pokemon fight.
The difference between that and this is that Ash actually
can battle them all. Well he could have done that in Unova too since they let him battle Gym Leader Cheren, but not Drayden and Marlon for whatever reason
Melony and Gordie can both easily happen. Melony could want to retire but Gordie doesn't want to be an Ice type specialist like her so she stubbornly holds onto the title(much like the drama in the games). Enter Ash and he helps the two get along by battling them both in the saga's obligatory two vs two match(Liza/Tate, Tucker, Olympia, Olivia, etc), Melony grows to appreciate her son's love for Rock types and allows him to succeed her as Gym Leader.
As for Allister, they never said where Bea's from. I think part of the reason she's roaming apart from their obvious love for her is so that Allister can be written as the Gym Leader
I think we'll see all of the gym leaders, it's Klara/Avery and maybe Rose's family that I'm more hesitant on as they can easily be replaced rolewise. Heck I still say that Bea's gonna be his rival during that eventual arc, he has quite a few Fighting types on his team so they might get focus there. Be nice if Scraggy gets to tag along too since Lucario, Sirfetch, Infernape, and Pikachu still allows for one slot on top of Kubfu, he could be buddies with Kubfu and
maybe become Scrafty
Cinderace, Grookey, and Inteleon...
Gengar's sure been appearing on a lot of stuff recently, I hope this means that he'll get focus soon or y'know just appear more. He's
well overdue for it