... Guys Jump is a magazine aimed at kids/boys, and I don't wanna sound prudish or anything but Jump doesn't even have that many main characters interested in their opposite sex (Most Jump protagonists are 'asexual' if you will, think Goku, Luffy, Gon) so they won't have a gay MC, at least I wouldn't bet on it any time soon.
And btw this is not because of Jump being homophobic or whatever, but simply because Jump rarely has MC who like someone, sure you have your Narutos or Sakuragis (Main Characters that had a crush on the female lead) or even pervert main characters like the dude from City Hunter every now and then, but Jump's manga rarely delve into romance (Of course unless it's a Romance manga like To Love Ru), that's why the motto of the magazine is "Friendship-Effort-Victory", those are the core values of Jump manga, not romance, and especially not romance between gay couples.
I am 100% certain most rational minded people can read a story with a gay lead and find it entertaining and enjoyable. Gay/Ace/Pan/Etc people read stories with Straight leads all the time and don't go "ew the lead is het? are you kidding me, get this unreadable het garbage away from me!" I am infinitely sure are gays in this very thread that read shonen jump mangas.
To answer directly to your statement, because it seems, it was you SharkBait and no one else, that for some reason started talking about Jump publishing shonen manga with BL elements in them (lol)...
Why? Seriously, why? Why would Jump do that? lol
I mean, Jump has 50+ years in the game, they have an established model of doing manga which clearly has worked for them, and I don't know about you but I really don't read any Jump manga expecting new romantic developments between my favorite characters (Sure, there are shippers out there, but most shippers are deluding themselves thinking their ship will eventually be real, and more specifically whoever ships 2 straight characters is just being plain dilusional lol)
I know Jump authors tend to tease these kind of 'relationships', it's very prominent in sports manga, but there' a huge gap between teasing something and it actually happening.
That being said, I think maybe a side character would be an interesting idea for an author to explore, but again, highly unlikely and even if the author wanted to (Which I doubt any author would dare/want to do that) their editor will likely prevent the idea from happening.