The game itself will be good but my god of all the things to base a game on
Basing a game on a game ain't really an issue.
And tbh, not like we haven't had stupider things, like a movie based on Battleships the boardgame, or a stuffty comedy based on 80s pixel games.
But why though, does something like minecraft really need a linear story
Minecraft doesn't need one. This isn't the canon of minecraft, like that stuffty end-credits scene.
This is just a story set within the concept of Minecraft, in the exact same way YouTubers have been making for years.
Except this one will have a team of professional writers who have made several award-winning games so far.