So...
Eh, I foresee if not this installment then a subsequent one - at some point in a Fallout game we're going to "solve" ghoulification. It seems kind of inevitable when I think about it, it's going to advance under the innate momentum of it's own themes. Of course we're going to run into scientists who want to cure ghouls in a Fallout game. I don't find that surprising at all. Given the setting in Fallout 4 we're inevitably going to be dealing with some themes around Science! and at least one NPC is going to also be looking for a cure. That only seems natural.
Barring any evidence or speculation on hidden clues and such, I can see where narratively it could make sense that one way to motivate the PC to help solve the ghoul "curse" would be to make them one in some way. In other words - I don't really see any of the evidence brought forward that there's a perk attached to being a ghoul as particularly compelling or convincing. But in kind of reverse-engineering the idea, it wouldn't surprise me if the path to curing ghouls led to infecting the PC. I think there's other ways to skin that cat (like if your spouse or son were to be the ghoul, for example, instead of the PC...)
But: I'd still rather see a Fallout game dedicated to that, if it were to happen. Ghouls are supposed to be tragic figures, I think. They work best when their demise is kind of a certainty I think (a la how their storyline wrapped up in the end credits in Fallout 1 and 2 - they all just sort of die off and fade into legend.)
If we were to cure ghouls of their plight and reverse their condition (we don't really need to worry too much about the logistics when we're playing a sci-fi game where Science! is wielded in the same way as a Sonic Screwdriver or Hyperdrives,) and we needed the PC to be a ghoul... I'd still rather see a game where that was the main plot. I'd rather just be a ghoul than make it a temporary condition like vampirism.
Just my thoughts, though - we'll just have to wait and see.