While I'm definitely curious how that all pans out, it's worth noting that at least for this year most USPHL Premier contracts were signed before NJ and Aston were announced.
What I'm more curious about is how long the league/these franchises decide to go with these teams if they're not making money. There's a reason the Tier II model hasn't been tried on the East Coast--people here want professional or nothing. Minor league sports don't work in the Philadelphia and NYC suburbs, let alone junior hockey. I'm rooting for it all to work out, but I struggle to see how it can.
Ummmmm....in baseball, there are several examples that disagree with you. Camden, Reading, Staten Island, Brooklyn, Wilmington, Trenton to name six. And, yeah, Reading/Wilmington/Trenton aren't really true "suburbs" of Philly but they are within the media sphere of Philadelphia so an argument can be made that they're more "exurb" than anything.
In hockey, Trenton was doing fine until the Devils trainwrecked the franchise and took the local identity out of it and the Phantoms were drawing well by minor league standards until kicked out of the Spectrum.
Minor league sports around here have had a better history than you think.
Regarding junior hockey, is it a function of arena size/availability moreso than simply "pro or no"? The rinks that the Tier 3 teams around Philly out of are pretty much barn size...there isn't any real decent sized rinks that could house a serious junior team unless it's at Penn (Class of 1923 seats 2500ish) or one of the bigger arenas out in Trenton or AC...and in those cases, those arenas are probably too big.