Yes I had heard this before. The small Honda turbo motors also seem to have severe issues with fuel dilution.
I'm actually running premium right now in the hope that I can reduce or eliminate any potential dilution by reducing the need to run such a rich mix. My understanding is that OEMs set up the fuel and timing maps such that the primary control of detonation is through using GDI to cool the cylinder. Which is cool and all but I think there's a better way, and that way is running better fuel!
I have to get through the break-in period and probably another 5-10k miles past that before I can get a good baseline on a UOA. For now I'm operating with an abundance of caution. Except with my right foot... it's not cautious at all