This could go a few ways. First, I'm sure Google will fight this and the fight will go on for some time. If they loose, Google could build EU data-centers and try to be GDPR compliant, which seems the most likely outcome. They could also pull out of the market, which seems less likely. If they pull out, I'm not sure that would be good for the EU market. People are suggesting that EU entities will spring up to fill the void, and thats probably true, but those services will almost certainly lag the benefits of the big US clouds. That may put EU entities at a competitive disadvantage.