As someone who's had Ikons x4 (including the screaming deal on 2 kids passes) for a few years now, and had blue passes last year but opted not to renew, this is fantastic for us.
We live in Philly and do a bunch of SLC and other Western trips each year , along with a bunch of weekend in VT so the Ikon always was a no brainer for us, but the lack of day trip skiing did suck. Got the blue passes for last year but my older kid needed a full pass , and with the generally poor conditions and many weekend taken up with travel skiing, only used them enough to break even on the cost. So we decided to not re-up and just deal with day tickets, despite blues sometimes outrageous pricing on weekend tickets with no discounts for kids. Looking like that gamble payed off.
From a corporate $$$ perspective, KSL owns both blue and camelback and is also an owner of Alterra who runs Ikon, so while Blue isn't an Alterra corp mountain ,it's still related and always seemed inevitable that they would be added to Ikon at some point.
My WAG is that Blue pass sales dropped a lot from the COVID boom after last year's no snow (I was called multiple times even months after the deadline asking if I still wanted to renew at the early bird price), so that the risk of the Ikon poaching full pass sales became reasonable to the mountain.
My guess is also for those of you who do more blue days and still need a full blue pass, they will eventually (prob next year but maybe sooner) add the Ikon add on option to the full blue pass, like how Killington, Snowbird , Jackson and the other affiliated but not Alterra owned mountains offer .