I kind of remember there being talk of plans for PSP games to have patches or features for dual analog on Vita (which would then translate now to PS5, ideally,) but it seems like few if any got that care, even Resistance on Vita doesn't seem to be genuinely dual-analog, the Right Stick is instead mapped to buttons or D-Pad and only bootleg patches allow analog on the second stick.
I never played Resistance: Retribution on a PS Vita system, as I only have the UMD for PSP.
From my experience with PSP games on Vita, the control remapping was left to the user. There was a lot of flexibility, with the ability to assign controls to the right analog stick, or even to areas of the touch screen. However, this only worked if the player made this effort in the system options. I haven't encountered any PSP games that came with "pre-mapped" controls on Vita. (I honestly don't know if Resistance: Retribution or any other games actually did this...just that I haven't seen any myself.)
Unfortunately, I worry that even Sony forgot that Resistance Retribution has the PSP+ feature for controller play...
This is Bend Studio we're talking about. They already went out of their way to inject trophies into a game they originally released back in the 20th century, when they were still known as Eidetic.
With that in mind, I wouldn't be surprised if they do remember this feature. The tricky part here might be the actual implementation. The controls were originally accomplished by having the PS3 (with Resistance 2) transmit the inputs through USB to the PSP. They'll have to find some creative way of "emulating" that portion of the control interpreter.
Sony has taken some creative approaches to similar cross-game and cross-system communication. For example, Jak X: Combat Racing on PS2 had some content that could be unlocked in conjunction with Daxter on PSP, by connecting the two systems with a USB cable. When they brought Jak X: Combat Racing to PS4 (as a "PS2 classics for PS4 release), they didn't allow you to connect a PSP with Daxter to unlock the extra goodies. Instead, they altered the unlocking requirements to work with saved data from the "PS2 classics for PS4" versions of the other Jak games. That was a good idea, especially for PS4 players without access to a PSP, but I wish they had also kept the original PSP method as an alternate option.