Wouldn't be a bit weird if MP1 gets a big work remaster, making it close to a remake (like Crisis Core) and then 2 and 3 also got rereleased but with just a resolution bump, or something not close to that MP1?
These terms have gotten so messy. Remake has always been a.... Insinuated thing, but the mastering process is a known quantity.
When making a game a bunch of assets are produced, audio and visual. These original assets are then compromised for various reasons, to either be able to run on the hardware, or in order to have larger areas or more objects, or fit on the storage medium that would contain the rom. When the time comes to turn all these original assets into the ones that would be able to fit in the rom and run with acceptable performance on the hardware, onto the commercial rom to be put on the commercial storage medium, that is called the mastering process.
When you revisit these old games for ports, you can choose to just take the assets already mastered the first time, or, if you still have them, you can take the original assets, now that you have more powerful hardware, and a better storage medium, and make a new master with them, with less or no compromises. Aka remaster them.
This is remastering. It's an actual technical thing that is done. Anything else is not remastering.
Don't know what it should be called of it's not a remaster, and doesn't make it's way to something that can reach consensus as a remake. But there is definitely a yes/no factual determinate to whether or not something is a remaster.