Next Era Predictions

I think it's both Rogue One and A New Hope (anniversary for both, although technically ANH's anniversary isn't until May, there are lots of content you can have in 2027 so maybe time efficiency)

it's also important to consider the loaned units, obviously Two-Tubes (both of them) is for Saw Gerrera, but we also have Reva, Asajj (Dark Disciple), Baylan and Luminara. all of these loaned units are weird if we only go for the Rebel/Empire route (although technically Luminara can end up on Saw's team because of the HoTs synergy), the only common thing between them is that all of them are Order 66 survivors, which is a stretch for Asajj. Baylan, Asajj and Reva are all DS UFUs, but then where does Luminara fit (unless CG put Luminara in there to throw everyone off)

regarding your list I think Bail would be more worthy to be a legendary than Galen, Galen only appeared in like Rogue One while Bail was a more central figure to the Rebellion as a whole