Update (22nd August 2023): Publisher Konami has clarified the frame rate and resolution for the upcoming Metal Gear Solid: Master Collection Vol. 1. In a statement issued to IGN, the company says the compilation has a 1080p, 60 frames-per-second "target" on all platforms (except Nintendo Switch). This means we can expect 1080p and 60fps on PS5 and PS4. It won't be reaching a nice and crisp 4K resolution, then, but it'll at least be better than the purported 720p.
What’s the resolution you associate with PS5 and PS4 games? On the latter, 1080p has generally been the standard, pushing up as high as 4K on the PS4 Pro. And the former format has generally targeted 2160p where possible, with a few noteworthy examples using checkerboard or reconstruction techniques to boost their final image quality.