Nobody forces Microsoft to exist in the EU, or to sell their software to EU citizens. They would simply be forced out of that market.
A workaround will be found, or one of the two sets of laws will be changed, or one of the two sets of laws will not be enforced.
I'm not sure how resilient this is to coercion by the US government. Maybe the US government could forbid Microsoft from doing business with the data trustee unless the the trustee gives up user data.
Your shell game you suggest will not withstand the scrutiny of an intelligent judge and an aggressive prosecutor.
Source: A lifetime ago, I was asked as a consultant to spec and site infrastructure out of the reach of the US government with the help of an international law attorney.
While I'd agree that small-ish foreign companies can probably fly under the radar, I don't think any company that receives payments from US customers is immune to coercion from the US. If the US government can impede a company's ability to access US customers then that's an ability to compel a company to give up data.