I would assert the only reason they pursued it in the first place is PR/optics, since the "optics" of not being able to proactively police what users do using E

I would assert the only reason they pursued it in the first place is PR/optics, since the "optics" of not being able to proactively police what users do using E2EE services you provide is somewhat a problem. That said, I think the concept of having your own computer covertly report you to the authorities is a level too dystopian to accept even from Apple.