Well, obviously they won't be able to use the same examples of amazing UA awards possible merely from the card signup bonus + a little bit of spend to promote their offers in the future...

So it will have an impact (I would think a relatively minor one) on their conversion rates/revenue -- there are still appealing ways to promote the cards even with the new UA program.

I am pretty sure there is no pressure from above to not relate the UA devaluation to Chase's points program. Obviously this is not in the bloggers' interest, though - why would they draw attention to it in a direct manner?