With the context you've added now, I might agree. Existing projects would be a pain to rename all files compared to adding a single line to the package.json .

About new projects, I'd have to read more about this new extension, for some reason it feels like a temporary solution that'll just get merged to the normal js extension in a future release.

Yeah it totally has the feel of a temporary solution.

From what I’ve read though, there doesn’t appear to be much of a plan apart from the current solution.

My initial reaction is that I want to keep all my files with .js extension.

One thing that could potentially be problematic is for files that need to run in the browser and on the server.

Really curious to see where the community’s tea leaves settle. My guess is that people will eventually just start using the new extension.