The best simple metric, if the thought of asking yourself “but why?” ever occurs when you decided to do a remaster, it’s best not to do a remaster.

If the capabilities of the hardware have meaningfully changed, a remaster is perfectly fine.

The PS5 is a far cry better than the PS4 in every respect. The PS5 version will almost certainly be a clear upgrade. And they’re not making anyone rebuy it; you pay the $10 difference between last gen and current gen games and you get the upgrade.