The problem is that some wallets will not implement it and some people may be very ignorant about it and which will not be good at all. The best will still be to have an upgrade which will be quantum resistant.
What I read about the post-quantum addresses is that the signatures will be larger because it is quantum resistant. There should be something that can be done or later proposed that can make the transaction fee smaller just like the transition from uncompressed legacy addresses to legacy addresses and later to segwit addresses.
You also said something that some wallets will be affected, especially addresses linked to Satoshi Nakamoto which have P2PK transactions. It is very possible that the coins will be unprotected even if wallet developers implement something like this. We really need quantum resistant addresses.
I just hope this quantum resistant addresses proposal will not divide the bitcoin community again in a way that will lead to hard fork.
we could just use more Silent Payments, that way address reuse would not be possible.
This will be good, silent payment can work best for people now but what about those old transactions that have tens to thousands of bitcoin and which are P2PK?