Which slightly incompatible version of TypeScript though?
edit to add: I'm serious. JavaScript tries very hard to not have backward breaking changes. TypeScript does have breaking changes at about ever minor release. The TypeScript team manages the project as a versioned tool, not as a distributed environment like the web. afaik, Deno hasn't really solved this problem, so there's a chance your code breaks when Deno upgrades its TypeScript version.
edit to add: I'm serious. JavaScript tries very hard to not have backward breaking changes. TypeScript does have breaking changes at about ever minor release. The TypeScript team manages the project as a versioned tool, not as a distributed environment like the web. afaik, Deno hasn't really solved this problem, so there's a chance your code breaks when Deno upgrades its TypeScript version.