I don't think it was ever alive. Nothing about the phrase "Derek Dooley floating the idea reportedly with the backing of private equity" evoked any confidence.
It's just too clunky to work while the G5 still gets a bid to the real playoff. Either you have a tournament to see who's the 2nd best G5 team (yay?), or you find a way to have the best G5 team play in both tournaments (logistical nightmare).
If it ever happens, it'll probably take the P2 splitting away from the NCAA or the P4 shutting the G5 out of the real playoff entirely.