If one of those addresses later happen to belong to someone else
The person you quoted was talking about the new Identity feature. So I assume this is referring to the Identity feature.
The Identity marker is based on your seed which is a random 32 byte integer. The chances of "one of those addresses late happen to belong to someone else" is very low, close to 0.
then it's clear money has in one way or another moved from my hand to that hand
If you had my seed, you would have all my bitcoins... sooooo, I don't think privacy would be a concern... losing all my bitcoins would be the concern. But like I said, the chances of having the same seed is close to 0.
If you somehow think this is not the case for stealth addresses, go ahead and try to explain.
Stealth Addresses? He was talking about Identity...
If you had my seed, you would also have the private keys to all my stealth addresses as well... so again, the problem would not be with anonymity, but with losing all your bitcoins.
I think maybe you are not an English native speaker? Could you try to explain what you're trying to say in detail? the more words you use, the more clues we have to go on when trying to understand you.