I'm pretty sure they can find a way to tell a story after The Rise of Skywalker, it's not like the whole Star War galaxy ceased to exist the moment the movie ended. They did say at the end that they still dealing with surviving members of The First Order, so that right there is a pretty nice opening for this movie.There's no story to tell in the ST. Hopefully it would be set during the GCW or its immediate aftermath.
Patty Jenkins has confirmed that this will be an original story, but that it will also acknowledge things from other versions of Rogue Squadron. Not surprised to hear that, since that's pretty much how they've been handling stuff from the old EU since Disney took over.