they won't do anything for sure. Google confirms it will provide security updates and google services to existing phones. Hardware wise, phone usually don't break within the yr warranty anyways so that doesnt matter. You just won't get Android Q update that's all. By that time, you are probably getting a new phone anyways. I won't worry too much if I was you.
I am sure the US companies will lobby to lift this ban. Huawei buys like $11billion worth of supplies from them. Of course they can recoup some of it back from other players like samsung but there will still be some lost to them.