It’s, what, 25 years old? There have been many sequels, prequels, remastering. The economic benefits of this IP are largely exhausted; that it is now leaked to the commons isn’t an alarming thing.
Recompilation efforts raise the bar for future re-releases, and incentivize proper remaster efforts like MGS Delta instead of the half-assed Master collection. I would love to see Konami thrive as a company and get more people interested in MGS, but their recent re-releases don't deserve to be priced at $60. Their monopoly of the source code feels like an existential threat to both future preservation and high-quality MGS remakes, it's healthier for Konami to simply let it go at this point.
And you don't even need to emulate it because there was an official Windows port... well you probably need to emulate Windows XP to make it even run.