Before everyone gets their knickers in a knot over the Y-wing in TROS, there are indications that this Y-Wing is the ONLY ONE being flown in the movie because it is a modified fighter belonging to bounty hunter Zori Bliss and not a fleet of them flown by the Resistance. So it's likely to be a modified, suped-up version of the base starfighter in Episodes IV & VI ala how Han Solo suped-up the Millennium Falcon to fit his own needs.
As far as canon goes - the show Rebels told the story of how the Rebellion got it's hands on Y-wings and why they looked like open chassis junk. They were the Old Republic bombers we saw in Clone Wars that were stripped of all their hull plating and essentials and were scheduled for disassembly and scrap, Kanan and his crew swooped in and stole about a dozen of them before they could be destroyed.
Yup. All told, this...
...inspired this...
...which then evolved into this in-universe...
...before ending up as this...
Koenseyr are probably doing other things, too, but after the declaration of the New Republic I got no problem with them wanting to capitalize on the fame of this craft, and that the most popular version was as the majority of people had probably seen it -- naked. I did not intend to imply that it was still being produced thirty years later. I figured that even these post-Empire Y-Wings are
still old ships. Older, ironically, than the original Y-Wings were at the time.
Or they could have looked at designs they already own (EU) and come up with something better. I think that part of it is their misjudgement that nostalgia is the only driving force behind fans' enjoyment, but I also think it's a little bit of the artists or director wanting his ideas/designs in a SW movie just because they can. Before that we had Lucas as the gatekeeper to go "Nah that's not SW." and either nudge the artist in a more Star Wars-y direction or veto the design.
I like the V-19 and V-Wing and ARC-170 and Naboo N-1 and so forth. Those all make sense. Look how many airplanes were buzzing around just on
one side just in the Pacific Theater in WWII, though:
P-39 Airacobra
F2A Buffalo
SB2C Helldiver
A-20 Havoc
A-26 Invader
SBD Dauntless
F4U Corsair
F4F Wildcat
F6F Hellcat
F7F Tigercat
F8F Bearcat
TBF Avenger
P-38 Lightning
P-51 Mustang
P-61 Black Widow
SB2U Vindicator
And that's just fighters and attack aircraft. Frankly, I wish we'd seen more from systems that chose to participate in the Clone Wars as the Republic Navy was getting itself going, in addition to the contracted craft the Kaminoans had ordered for the army they were making. As it was I'm glad we got the Z-95 Headhunters... I just wish it hadn't been so late in the Clone Wars series, and wish we'd seen earlier versions in TPM or AOTC, perhaps. Per the lore, when they were created, they'd been in service for well over a century, and the design had evolved drastically from how it had been first conceived. It would have been some nice visual storytelling in the setting, with the early Z-95s transitioning to wartime models, the last of which (in ROTS, maybe) had been modified with spacefoils that split into a shallow X, with twice the armament, as a predecessor to the T-65. This, then, would have tied things together further with the T-70 and T-85 of the post-ROTJ era.
