I just wanted to clear the air here, my argument isn't the same as
Mibu no ookami
's argument. I'm not implying it shouldn't follow source material. To be honest I'm not sure if many here are even suggesting that to begin with, so I'm not sure why the conversation was turned in that direction. I'm saying that source material must be slightly updated when going from game to film, the same way it is updated when going from book to film or manga to anime. The presentation simply does not work 1 to 1.
Too add onto that, the source material argument has absolutely nothing to do with the 80s theme that you're bringing up. I'd argue that any 80s theme that game has goes out of the window the minute Snake goes into the political intrigue aspect of the movie and meets a Cyber Ninja minutes later. MGS was one of the many trendsetters for 90s properties regardless of how the main character was inspired by a single character from a single 80s film. I think the film version should also not shackle itself by the bounds of being 'old school' just to please a small minority. If they want to do more popular things like one take action scenes(which a ton of 80s films did not do), or utilize a pacing that matches the espionage genre of today, then maybe that's the better call.
Edit: And I wanted to add a small opinion about Uncharted movie. If you look past the two main actors and how their characters' origin stories were changed, a lot of the film stayed true to the video games. Drake is visited by Sully who tells him that there's a new score of possible treasure. There's a bad guy with goons who is also 'racing' with them for the same treasure. They go from location to location finding clues that they books, maps, and other clues from the explorer of the past. Because of shaky allegiances, changing sides and betrayals happen due to Chloe. The issues are resolved, they team back up, epic set pieces happen between big bads and the protagonists and they end up finding out the secret in the end but only keeping a very small amount of the treasure(like the first 3 games). Doesn't that sound like Uncharted?