Yeah, this sounds like an assertion that is entirely based on wishful thinking rather than evidence. Don't get me wrong, it might be true -- but you really need to provide some evidence if you're going to make claims like that.
It’s at least plausible. The traditional definition of herd immunity assumes a homogenous population as the term has mainly been used in a vaccine strategy context. The above paper revises the definition based on a heterogenous model with the conclusion that the dynamics may be quite different in an actual epidemic.
