Sorry I shouldn't have said I don't care. Let me rephrase: given a typical use case of Phoenix, e.g. transacting with merchants (who use typically specific software like Btc Pay server), the privacy aspect will get better with Bolt12 and (IMHO good enough). I see other use cases like sending or receiving money to close peers, using Phoenix, as more rare so not a significant issue. For this use-case though, namely transacting with friends or close peers, I see more something like ecash making sense given that privacy is the default and it has very low fees.

What you describe looks to me like Signal, they log every time we receive a message from someone, in terms of privacy it doesn't look critical to me given that Acinq doesn't know the origin. The main privacy issue I see (and didn't know before) is for transactions between Phoenix users mentioned above.