I'm not sticking around, but you guys are generally so upbeat and the mood here is depressing me.
For starters, even if Kendra did get shipped with J'onn, that doesn't mean that John can't get a new love interest too. Not that she's going to be. The word "relationship" doesn't automatically mean "romantic relationship," y'know? And from a narrative standpoint, it would not make sense for Kendra to frequently bring up Carter and what he means to her if Snyder were trying to build her up to be with J'onn. The guy's a writing professor. He knows how to properly set up a narrative.
Also, Kendra's a Hawk. She's not getting shipped with anyone but Hawkman. That's their thing. Interesting to note, though, that the same is not necessarily true of Shayera, and so I wouldn't be so quick to write her off. If you paid close attention to Justice League #16, what it actually did was remove her from the reincarnation cycle.
Take a step back and look at this from a storywriting perspective. As I'm sure you know, Shayera had actually been dead for quite a while. Snyder retconned that so he could bring her back and disconnect her from Hawkman. The Hawks are always together so if you split them up, it's obviously because you don't want them together. And if you don't want them together, it's probably because you want at least one of them with someone else. (Shayera wouldn't HAVE to be removed from the reincarnation cycle to be shipped with someone since Katar is dead, but full-on disconnecting her makes the ship much less likely to be undone later.)
Shayera will be back, and she's getting shipped with someone. Considering how much Snyder liked the ship in the animated series, that may very well be John. Prooooobably not going to be a major subplot since I doubt there will be two Hawkwomen on the team at once, and with Kendra already stated to be a main player, Shay's probably gonna be supporting cast. John needs a stronger supporting cast though so I think this could be great for both of them.
So chin up! John may very well still have some cool stuff in store.