It’s speculated by random people on the internet.
Not necessarily by anyone involved in the ECAC.
Every time you see an ECAC coach, admin, commish, etc. on the USCHO, CHN, or any other college hockey podcast, they are always saying how satisfied they are with the status quo. In fact, even when it comes to membership, the ECAC is the most status quo league in college hockey. They added Union when they came on board and took in Quinnipiac when Vermont went to HE. And that’s the only changes they’ve made since the birth of HE. They’ve even been the last holdouts in shootouts and the like. They don’t change easily.
Thats not saying that they never would (especially if Penn came back and/or Columbia apparated from nothingness), but the Ivies have had the ability to split off if they so chose for A LONG TIME at this point and haven’t.