Blizzard could also try to make use of temporary shields like Lucio, Doomfist, and Hammond's. Along with some sort of damage resistance/reduction like what Orisa has.
There can only be so many different ways to heal until Blizzard ends up making similar healing methods. Geoff Goodman pointed out on a Twitch stream that they were concerned about making more heroes that would end up copying and feeling like other ones. More heroes like Orisa and Brigitte (who feels like a Reinhardt/Lucio hybrid somewhat to me personally)
Is it a bad idea though? I'm starting to think one of the reasons that the meta gets stale so often is because you have single characters who fill single niches, thus when that niche is in favor they are meta, and dominate anything else. Having more variety in each niche sounds like a better idea. Even if it means we get another hero like Rein with a mobile barrier, or another hero who boosts teammate speed, or whatever. As long as those heroes are unique in other parts of their kit, it should still be fine. There are several Damage heroes who all fulfill similar roles (Ashe/McCree/Soldier/Widow) so why can't the same happen with tanks and supports?