Yep. My mom came from Greece as a child in 1952. She and her 6 siblings, aged 4-17, were all put in kindergarten and moved up to the next grade when/as appropriate. Her parents never learned English so school was the place the kids all learned.
I think it was the best way. I once wanted to move to France for a year so my kids could learn French. This of course wouldn’t have worked if they had been taught in English.