I mainly see this as a QOL change and a reduce to general chat LFM X 16man run spam.
It's not really going to change much. The nucleus of the team will queue to fill in the gaps. With 16man being faceroll difficulty it doesn't really matter much if you get a few under geared or clueless pugs. Not as if there's a huge amount of vetting in fleet chat for these operations as is.
And on the flip side it makes it more accessible to get into raiding for new people/people without a guild or enables them to check out the story.
I can't really see a down side. If 30 ultimate comms are the problem a HM run will still net you more with drops each boss + weekly.
And I want to take time to give you props for sanity and objectivity in the face of silly sauce.