> I can't guarantee this is novel paper in general, but it's not something I've seen treated this formally before

Yea, I'd be very happy if they just said "here we make formal the possibility, considered since the paradox was first proposed, that there is enough uncertainty in each parameter that seeing zero ETI is perfectly compatible with expectations". That would have been a modest but useful contribution to the lit that would have informed further research. The issue I have is with claims that they are "dissolving" anything.