That's a false narrative.
GTAV on PS3 was entirely different architecture than the PS4 version. Everybody worth their salt knows how difficult it was trying to code around the cells and split memory environment the PS3 featured. PS3 was not BC with the PS4. The PS5 will be bc with the PS4. That's what's different. Also, in case you forgot, Rockstar allowed you to carry over data from the PS3 version of the game to the PS4 version. They continued to support the PS3 version of the game for years before pulling the plug (due to exploits on jailbroken PS3s and waning income generation). Same as Daybreak did with DC Universe Online. They kept the PS3 version afloat for years until pulling the plug when it stopped selling and the userbase grew sparse on that platform.
If Frontier wants to release a free patch that will install enhanced visuals to the PS4 version of Elite, when played on the PS5, that's up to them. It's doable, and publishers have done similar before. Just the same they could release a VR patch as well (though there would be a cost associated with R&D for coding on the PSVR2 - which would cost even more if space legs and ground combat do become a thing). No Man's Sky, made by an indie studio, got it's free VR patch. Nobody had to pay anything for it. In a reciprocal case, The Persistence received a patch that allowed the game to be played without the PSVR (was 'VR exclusive prior to).
Obviously VR tech is the future of gaming. If you've never played on VR (especially the higher end stuff on PC), it's absolutely ridiculous. Even people like me with pretty bad eye issues can use the PSVR. Sony's not about to give it up, and they are going to be making a big push for the PSVR2. Recent shakeups at Sony pretty much saw the western end of the spectrum secure power to enforce the push and adoption rate of the PS5 from the 4 at levels that have not been seen before. It would seem there was stagnation on the Japanese front, where gaming itself is in a long-running state of decay. With the western division spearheading next gen, it gives them everything they need to entice publishers and developers to get on board with next gen, including VR.
Like said already, a lot of publishers have been disappointed with the PSVR due to it's lack of flexibility and performance. It's like coding for last gen standards. That's not what sells. That's not fire and it isn't going to get the masses to spend and invest on fairly expensive equipment. What was also limiting was the PSVR's controllers - the outdated PS Move wands that feature horrid button placement and a lack of PSP-like analog sliders or even full analog sticks. Too many additional peripherals end up being thrown into the mix like the new gun with built in analogs, and now they have rudder foot pads, all in an effort to resolve the issues with interface and lousy controls. (Instead of, you know, just making new move controllers with an analog each). Unfortunately we have no idea if this issue will be resolved as we only have hints of patents for a new move-like device they're working on, but very well may end up still quite limited.
At least when it comes to Elite, you'll be able to play using your regular controller and the VR headset, or flight stick & headset. Might get a little weird if we do get ground combat, though. Trying to play games like Farpoint using the controller was definitely a less than stellar experience. If they decide to make aiming function with simple head look like REVII did, could get around a lot of potential issues.