So, the Legion just got confirmed for Young Justice (the show), and as you all likely know, Jon Kent is already on the show as a baby.
With a straight up 10 year timeskip being more or less unlikely at the moment,
the show's pretty strong track record with with paying homage to the comics and even current day stuff, and there apparently being some sort of media aspect to Bendis' deal with DC, chances seem pretty good that we may get Jon Kent in an active role as part of the Legion of Super-Heroes in Young Justice season 4.
Or it could be through a time travel episode, but that'd just be a cameo, and I'm much more interested in something more long term. Like maybe something where a handful of Legion members have to be in the past for some reason.
Given the fact that Bart is in the past, he's much younger than Jon would have to be by his time, and this is very much a capital T teen drama, I'm thinking there's a fairly reasonable chance that teen Jon may be the go-to. So we may get like a 3 or 4 year old Jon in the present, and a 16 or 17 year old Jon coming from the future.