Remasters or late ports often get worse scores than the original. That's certainly not uncommon not even for games that used to be the GOTY of their year.
Bioshock Collection - 84 Meta compared to the original releases of Bioshock (96), Bioshock 2 (88) and Bioshock Infinite (93)
or
The Elder Scrolls V: Skyrim Special Edition - 81 Meta compared to the original (96 Meta).