I'm not sure what you're really going on about here - there's a massive amount of proven history of EU/US law enforcement using each other's surveillance techno

I'm not sure what you're really going on about here - there's a massive amount of proven history of EU/US law enforcement using each other's surveillance technology and legal loopholes to exchange information. War on drugs, CSAM, human trafficking are oft cited reasons. There's pretty much zero chance that US would reject use and insight into private communication if EU puts it into law and forces upon messaging apps. We have literally pile of historical examples where FBI & co. were actively pushing for more of such data sharing programs. - So what exactly is your point? Where did you get an idea that you'll be running "EU software" and that US will defend you if you get into a CSAM suspected database list?