I would be comparable to the Gen 3 reboot, but hopefully better-planned.
The Gen 3 reboot was very unexpected, done only because of a lack of trading compatibility between the GB/C and GBA. Most people expected RS to continue in GSC's tradition and be another sequel that built upon the first two Gens. The Johto music and Cable Club dialog hidden in RS' data possibly indicate that the games may have very well originally been planned as GSC sequels.
Very few anticipated the hard reboot we got instead, and that alone turned a lot of older fans away from Pokémon during Gen 3. Even if the hardware necessitated it, it was way too soon to be rebooting Pokémon. The first two Gens were still well under a decade old at the time, and the older games (especially Crystal) were even still on store shelves by the time RS came out.
A hypothetical Gen 7 reboot would happen under different circumstances. First of all, it would be something that GF actually plans out instead of only doing because of hardware limitations, so the transition would go along much smoother than it did in Gen 3.
And, Gen 7 would be coming off of several long-distant Generations rather than only two still-recent ones. Even BW are more than half a decade old now, and all of the pre-XY games have pretty much vanished from store shelves now. Only XY and ORAS would really get cut short by a hard reboot, but let's face it, based on the games' lackluster sales and reception compared to RBY and GSC, there would be fewer complaints.
And, that brings me into my last point--The mindset of the fandom is way different in 2016 than it was in 2002. Enough time has now passed for many fans to have simply become tired of Pokémon and seeing the same formula repeated in every game over and over again, while the franchise wasn't even old enough yet for that to have happened in the early 00s.
(It also helps that GSC didn't repeat the same formula from RBY verbatim in the same way that all of the later games (especially DPP and XY) have been some variation on the formula from RSE--brand new isolated region, brand new Regional Dex focused on brand new Pokémon (many of which are obvious expies of older ones), opposite gender PC is a friendly rival you cannot name, Team ______ wants to use the Box Legendary to destroy the world, Champion is a friendly young adult character who first appears midway through the game to help you against Team ______, final showdown between you and Team ______ happens exactly between the 7th and 8th Gyms, post-E4 postgame revolves around a Battle Facility of some sort, and so on.)