That may be true. When we moved here from the U.S. one of the reasons we choose Lloyds was because they made it easy for us to sign up, and the reason it was so easy was due to knew policies to attract recent Polish immigrants (which of course applied to anyone, not just the Polish).
We just used my husband's work address to set up the account because we didn't have a permanent address yet. And to prove his work address we had a letter from his employer offering the job, I think. So I guess they did need proof of address, but that was a lesser proof of address than anyone would accept for anything else (like even going to an NHS doc).
It makes sense for the banks to find ways to attract all the Polish workers coming in, that's business they could miss out on.