I also like the idea of SWG > New Canon > Legends if just so we have the opportunity to include things like Scarif and potentially future films into what we do in SWG RP. However, I think a lot of us come from playing games like SWTOR, which is one game technically out of New Canon that we would like to imagine is still part of things. After all, we've created characters in the Old Republic and some of us have studied up on Old Republic lore for the better part of 4 years now (even if it is hardly relevant in 0-3ABY). On top of that, I know some RPers will be playing their characters from live, and I imagine that many of these characters have had story arcs including now-Legend story figures or powers.
Ultimately I believe that every single roleplayer here wants to use at least some amount of Legends in their roleplay. I don't believe that any roleplayer will be ignoring people that incorporate common Legends themes, and if they do, I don't believe that they will be successful in working with other people. After all, a lot of RP is focused on sacrificing bits of an idea so that others can collaborate with you. We are also playing a Legends MMORPG.
In the end, I think being courteous to one another will go a LONG way when it comes to canon vs legends. I remember being extremely young when I started playing SWG, having no idea about any lore, and being ignored for not understanding a lot of basic ideas. I wasn't the type to argue, I simply would not know something and would meet the block list when it was made clear IC. Since then, I've tried to explain things to people in /tells and, at the very least, reach a middle ground when there's discrepancies between my vision and someone else's. Not only are we a small community that doesn't want to fracture, it's just plain rude to ignore people who have a different concept of what is right and what is wrong in such a complex setting. If it were easy, we wouldn't even have a thread like this up.
tl;dr: If you don't like acknowledging battles, people, etc. from Rogue One or new-canon media, have your character not recognize it and maybe send a tell to the other person. If you don't like acknowledging Legends content, have your character be ignorant of the various PoIs across all planets. If you cannot do either of these, there's likely other ways to compromise or work around the problem.
But to reiterate, I really would like to acknowledge the battle of Scarif on a Rebel character. At the same time, I would like to move around Yavin without fear of bumping heads with someone on if a temple is really there. I really hope that most people are in the same boat and that we're all trying to have fun rather than make the setting into a serious chore.
I've not seen every episode of Rebels, nor have I read any of the new-canon books. I can't imagine that every other RPer has, either. It would make sense to acknowledge the core of lore over these things and I think it comes down to expectations and reasoning with people rather than "canon or legends?"