You don’t have to listen to me on this one, but I personally think that SWSH won’t base their evil team on real-life British things. Skull and Aether aren’t related to Hawaii, Flare isn’t related to France, Plasma isn’t related to the USA, etc., and I just think trying to bring real life issues like British politics would just feel out of place in a Pokemon game.
I think the team will be based on the region’s current situation, rather than its real life counterpart situation. Alola frequently has Ultra Wormholes appear or open, and Aether existed to study them, while Skull was full of people who had failed their trials and had nowhere else to go. Kalos still had scars from a war long ago, and Lysandre didn’t want to see war break out again. Unova is a very urban, battle-based Region with multiple types of tournaments across both Unova entries, and Plasma originally existed to challenge this. (Later on they were just run by a man driven crazy.) We can keep going back and look at the rest of the regions too - Hoenn suffered frequently from natural disasters, and one of the two teams in those games tries to put a stop to that based on their own ideas and morals. Kanto also has remnants of war, and a mafia group could easily take advantage of a region in such a state (and Johto was just their next target). Sinnoh is a very religious region, so it makes sense that a lonely man would look to his gods to try and make his goal a reality.
Thus, I think SWSH’s evil team will be based on the region’s lore and/or current situation. Considering we’ve already had emphasis on technology and industrial feats, we may have a team based around those. I don’t think they’ll go all “save the earth” on us - it’s oddly reminiscent of Team Magma - but I think it’s possible they’re trying to further technological advances using the legendaries. Maybe a new piece of info later down the line will change my mind, but for now this is the best idea I’ve got.