Not likely that they'll expand to EWR, as much as I'd like them to do so. EWR-SFO, they're the only airline operating this route. EWR-LAX, you also have AA, but they aren't providing a premium product, so no competitive reason for UA to do so. Out of JFK, OTOH, you have DL's domestic BE, AA's flagship, and I'd even go far enough to say VX. I know a bunch of people who will even fly B6, as it's the most comfortable Y product on that route. (Same seat pitch as current all E+ on p.s.)

Why do you hope not? If you generally fly p.s. and it was expanded to EWR, how does this negatively impact you? If anything, it's better as you now have more choice.