It doesn't matter if the game server (according to the Steam overlay) is hosted in London, Stockholm or Helsinki. Almost every player in every match are from Russia or speak Russian. It is a pretty bad experience for everyone else. Feels just like CS and DotA.
which means they can very likely not be russian and just from the CIS.
Chat wheel is enoguh to communicate many things but because heroes have different names in different languages ( i think its bad, if i say dynamo or anything similar a brazilian russian and korean can get its dynamo even if said slightly different) but generally Go/Back/davai/LFG goes accross everyone, if you want them to understand your disertation on why you are right and that was bad i don't think that's the issue of the servers as you can have region locals that also dont speak english and that doesn't seam to a problem for some reason.
World events have made this more prevelant, because the server sees they are located in EU. Now does a brother from UA need to be called a russian because he uses a cyrilic language, you don't know but that probably tilts them off the earth and only hear the screams.
I've played all the valve games where you are very often paired with eastern europe bratans and I have foundthe same ammount of griefers and bonehead people in every region, people just pick the ones that can't defend or you can't understand as scapegoats, NAdota is peruvians (speak a spanish language = peru).
I believe the game does try to create games faster if it has players. they are working to make mm system better but right now the majority of people have low playtime nad come in with very different skill sets and expectations so the system when playerpool is lower (not peak times) they tend to go wider to get people. I see sometimes i am 1v1 with someone who hasn't done the tutorial, sometimes i get farmed. i have encountered people from eastern europe, played just the same, ping what you want what is down when you go who is low and keep moving.
Try to separate your bias and emotions towards who you are playing and tying to the result to what yo can do and what the gameplay can be better at.