It's too cheap for a leather bound version, that would be way more expensive then even the alt cover gift set.
Plus there were hints of a sort, the detailed surveys on PHB races/subraces and classes that was checking customer satisfaction with each race, it's features, subraces, and things folks would like to see changed, I knew when I took that survey that 5.5e of some sort (and they might not call it that of course, but really since Tasha's it's 5.5e already, it's just the core books haven't been updated to reflect that yet).