I suspect it was because they had little else going on for either of them in that last season, so they drummed it up to just give them... Something, which was not uncommon back then, for tv writers, who just gravitated to relationship drama, when they had nothing else, & fell into apathy or creative exhaustion.
Case in point, they also upped the Beverly & Jean-Luc thing too, with Attached & AGT, which they hadn't even hinted at for years. Beverly was resoundingly overlooked in season 7, except for one of the shows most ridiculed episodes. That was all they could churn up. "She gets cozy with Picard again"
Hell, they'd been so apathetic about Geordi, that in AGT when trying to conjure up a future life for him, some genius just said "Hey, who's that women he had a crush on & made it very awkward & creepy, Leah or something?" "Right. Her. He married her & has kids or whatever"
I mean geez, even Riker/Troi ends up working out, after years of stagnancy about it, when it would've made more sense for her to rekindle with Tom Riker (who didn't ghost her like Will) after he'd spent a decade pining for her.
Star Trek never wrote good romance relationships imho. Their hit or miss dabbling in comedy even went over better