I for one never understood why Halo was so popular in the first place, the series is good over all and any score between 8 and 9 is pretty amazing for any game or game remake to have... I mean, I understand it has great shooting mechanics, an interesting setting, a mysterious world to discover, very nice sky boxes...
Now for the Uncharted remakes, the mainline titles scores are 88, 96 and 92, they're relatively new, many people prefer them to even The Last of Us, so it would probably score around 90, just like the Halo:MCC remake.
As you said, as far as remakes or remasters go, this bundle is pretty amazing, they did the best they could do with the Halo games on the XB1, offered tons of content, etc. but the reviews judge the quality of the content, not just quantity... otherwise the car game with the most cars/open worldness, etc. would automatically get the highest score, oh wait this is how driveclub had its scores taken down compared to forza horizon 2, I mean, you could literally read MSes PR talking points in the Driveclub reviews on many sites! this is true bias, not when a game get 88 a metascore of 88 instead of 92.
Perfect scores are for the likes of The Last of Us, Uncharted 2, God of War 2 or 3, a couple of Zelda games, some Mario titles, and a very few others, we should not see them every year (unless Naughty Dog releases two titles in the same year).