I would be a bit upset if it was a new edition...but it doesn't mean older content potentially couldn't be salvaged.
I personally would prefer a soft reboot with a core rulebook that acts as an errata to the old and revision of mechanics with a way to grandfather older stuff in. However I also understand the logistics of that are not possible and when you band aid a problem you're just covering it up and patching it, not really solving the original problem.
That being said, to me there's not a lot that I would want to see revised. Starship combat definitely needs a revision but beyond that...some of the earlier specs definitely? Nothing else really leaps to mind.
The advantage of a new edition is its a great jumping off point for new players, and a lot of the ground work has already been done. When EotE was released, I imagine Lightsabers and Force Powers etc were not really fully finalised until F&D, with everything now have a basis to work from in theory it means a second edition can be tighter from the start with potentially more content.
Would I not buy a new edition? Come on, of course not it's Star Wars RPG. I own the entire line including the rare Rescue at Glare Peak. I'm not exactly going to break my collection now especially when it's not like we are getting a book every month. I have the disposable income to easily afford a new book every month and not blink (but please don't do that FFG. I do like having some money for X-Wing and other things too...)