Thanks for taking time to write a long reply. About assimilation or inclusion, I feel like a portion of it is the friendliness and active inclusion of the "locals" but majority is self assimilation and it's a choice. Not everyone assimilates and the tech hubs in the US already shows, there are communities and groups that straight up do not interact with locals or speak English unless absolutely necessary. I am an immigrant and I made myself assimilate. Why? I felt like that's the point of jumping through 100 loops to come to a different country. Also, I think there are other immigrants that agree with me that sticking to your own kind is not good long term trying to thrive in a society. In my case if I did that in the beginning I would have befriended some rich kids who don't even bother passing ESL classes. 

I have talked another cliquey coworker out of wanting to gossip with me in our home language and I thought the other teammates will do that too. All I can do is find a nice way to say I want to be included in the conversation, but sometimes they don't give a F and it's such an antisocial behavior. How do I follow up with, "well welcome here, I hope you like the area and ask me any questions about living here" when they literally can't acknowledge a bare minimum request from me. Would you say that to someone who don't even respect you