So uhhh... What mons would you like to get in to benefit the
developing metagame? FerroPex has our defensive backbone covered for now, so right now I'm mainly hoping for more Fire types to alleviate the current shortage as well as more bulky Fairy types to take on Weavile better.
There also seems to be a shortage of Bug Pkm (Golisopod, Vikavolt, Vespiquen, and Butterfly, if I recall right). I hope the creators will surprise us as they did in gen 5 and gen 7 since the Bug Pkm were useful in their own way. Speaking of Golisopod. It would be nice to see its ability getting a buff, say, you have the option whether or not you want to switch it out. It would make more sense dex wise as it's described rather as a tactician than a coward in disguise; after all, there's not really a difference between Golisopod's and Wimpod's ability, except their names, of course.
Anyway, it would be cool to finally see a non legendary Bug Pkm able to set up Trick Room! It would add more diversity since Bug mostly relies on Sticky Webs. Maybe, we'll see a Bug/Psychic or a new Bug/Ghost Pkm this time?
While not really a benefit to the metagame, it would make sense to give Queenly Majesty to Vespiqueen or, if Masquerain will make an appearance, to give it Drizzle. Seriously, it literally has rain in its name!
Then, we have Hippowdown. It's good as it is, but Shore Up would be a nice addition, and it would also make sense.
Now, I noticed we have many Pkm who can summon weather. But what about terrains? I don't think the Tapus will return in the Galar region, but maybe we can expect some non legendary Pkm able to set up terrains through an ability?
On another note. Gen 7 offered us pretty useful Pkm, with a major focus on Bug, Poison, Grass, and Fairy, which are all good in different metagames. So, I hope less used types will still get some new useful additions.
Last but not least, in almost any gen, we had a trio or a quartet of legendary Pkm who all had a theme in their respective gen. If we get another new group of non uber legendary Pkm sharing a theme, maybe, this time, the creators will focus on Dragon or Ghost? We already had Flying, Psychic, Fighting, and Fairy. But so far, no dragons or any ghosts. Dragons seem to have deep folklore in Britain, and Ghosts represent the supernatural. Apart from that, I think we can expect many new Fairy Pkm since fairy too have lots of folklore in Britain; after all, you have Tolkien and Spencer's
Fairie Queene, an allegorical work in praise of Queen Elizabeth 1, and fairytales in general. Speaking of fairytales, wouldn't it be nice to hear a Pkm version of fairytales or to be in some sort of a fairytale? There's one place from the Galar region, which gives me some Alice in Wonderland vibes.