The DefinitelyTyped repo is being treated as the endorsed community repository of type declarations for packages that don't provide their own.
Answering this question depends on what you mean when you say
submitting them directly to NPM.
If you mean including the .d.ts file with the package that the .d.ts file corresponds to that's encouraged. The moment package, for example, includes and maintains its own declaration file.
If you mean providing your own type only package then DefinitelyTyped is the better location for those files and will provide some advantages. By including your file in DefinitelyTyped it will
- benefit from automated deploys to the @types namespace by the TS typings bot.
- which will also yield predictable module resolution in the compiler.
- be in the long established source for typings. You'll be where people are looking.
- be more easily maintained by others.
- the package will be easier to find
- maintainers will use a workflow and format they're familiar with