Is it that big of a deal? Genuinely not trying to be funny, as i'm not very familiar with the franchise. Or are you saying it's a massive announcement to you, personally?
LucasArts adventures including Monkey Island were big on PC back in the 90s. People who grew up on consoles probably never heard of it, which is a shame. Generally, LucasArts was great back then.
Return of Monkey Island is great, not only because it is a new entry in the franchise, but it is actually headed by the legendary designer Ron Gilbert, which is a surprise because he said he will never do it again. He is also joined by a lot of names that worked on the original game like Michael Land. So yeah, I hope it goes as well as the original, which is among my most beloved games.