I have personally never heard about this issue. I've been using headphones since quite a young age and have not noticed anything of the sort. Anyhow, I don't think it's ever a good idea to spend too much time obsessing over skull shape-- that's what phrenology is, and they got nowhere.

Is this the political position of each codec?

This is the exact setup up for demo at my local headphone store so I can positively say that it's probably wise to stop here for your wallet's sake!