Because the previous ads for Pocket and Telefonica were effective and they don't care?

I hardly think it's a lie. My browser contains no trace of anything related to Looking Glass, even though I'm opted into Shield Studies. It seems to affect some people but not others. Definitely something that should be fixed in the core mechanism of how these things are downloaded by your browser if there are cases where it can happen without user intervention, but it doesn't seem to be intentional to download extensions without the user's consent.