Frontier is pretty lousy with their information policy. I never received (at least can't remember) an email with information about it. I see this as a serious devaluation of the product for frequent fliers. Their current seat pitch was ok for me but now it is really squeezing it.
I am Summit but even with the status you won't get it except via online check-in (24 hours ahead, almost sounds like the Southwest game now, check in early).
I do not like this change at all and might just consider moving to Southwest for my low cost flying. I have E+ with United for free.