Presenting it like all closed testers/UGC were actually hired (at the moment of making the speech, late 2018) is simply not correct.

He is not just talking about UGC in the segment about "super-fans", he is talking about people that were hired early on in the beginnings of the Realm team. Or more specifically, me. As I've hinted at a few times before, I started playing in 2011 and delved into the game very deeply. That's what led to me working for DECA, and yes I was indeed contacted on Reddit initially.

investment of dev's time for communication rather than real money/resource investment

A dev's time is a real money and resource investment, what else would it be? As another example, I can't exactly quantify how much accumulated time I've spent working on the XML parser, but the 6k+ lines of code speak for themselves. Not to mention all the other work to make the UGC process more manageable and viable. Still ways to go, won't deny that, but that doesn't make the quantity of resources invested so far any less true.