Your mind seems made up on something that's not even definite given Kishimoto's mercuriality when concerning pairings. He had fans fooled into the prospect of NS for years, he can do the same again.
And personally, I find the idea of Sarada and Boruto whimsical. It works on the abritary, but pragmically as at all angles a destined ruin of the manga. Unless Kodachi and backup writers can continually drop hints here and there, and make room for the two while not jeopardising their roles as main characters. Sarada is confirmed the deuteagonist of this series, so her relevance and input will be an equal share of Sasuke's if Boruto is to be a replica of Naruto's story where much focus gravitated towards him, but Sasuke also seemed to be drawing a good 1/2 of it and even more-so with the Uchiha controversy.
Plus, the last point which you casually added seems to be the more realistic case. The Sharingan is already becoming a lore and mythical power that died with the Uchiha clan, the modern world doesn't seem to be aware of it, outside shinobi's, and the Hyuuga seem to be branching out and amalgamating with other clans, since the shackles of the law statute had been raised, with Hinata marrying an Uzumaki and dropping her Hyuuga name. Hanabi seems to be heading down the same route, and other members, who are no longer compelled to incest, could be following in the same footsteps. Which can only lead to the inevitable extinction and dilution of the bloodline, subsequently, similar to how the Uchiha clan would have died out, if they hadn't been lead to an earlier death as a clan.
OT: not so keen on seeing the resurrection of the Uchiha clan, to be honest. The narrative painted it in such a wat that Sasuke is meant to be the last pure member, and I would like for it to remain that way, ceteris paribus. But if it so happens other clans rise out of the ashes, such as the much revered clans that roamed undetected, like the one possessing the crimson doujutsu that even the Byakugan couldn't compete against in the filler episodes and Kimimamaro's clan, I wouldn't mind a nostalgic reunion between the clan's, and for the Sharingan to get its shine in a conventional old style battle in which tactics veritably apply.
But if the Otsutsuki keep flocking into the nest of Naruto-verse, I'm rather glad their existence is not continuing. It wouldn't look too well experiencing all this with the Uchiha in the same picture, the Otsutsuki don't deserve screen-time alongside greatness.
