Only because the US refuses to properly protect consumer privacy and seemingly can no longer be trusted at all. If Trump forces Microsoft to turn off Office 365 for example for the EU, or blocks AWS, GCP or Azure from doing business with the EU then European businesses are screwed. We’ve now realized these risks are potentially real and European countries are scrambling to look for alternatives (and realizing that they don’t really exist).
Considering the PCLOB has lost some of its members, it's questionable whether the DPF can continue to exist in its current form. If it does go out the window, then Trump won't need to tell AWS/GCP to stop doing business with the EU, since European companies wouldn't legally be allowed to transfer data to US companies anyway.
I expect the EU commission will take a _very_ long time to actually act on this tho. Maybe we'll see Schrems III first.