With the rise of unpkg as a CDN for published bundles, would it be acceptable to publish a browser consumable bundle with the NPM package?
No. Please use webpack or similar.
Anyone who excludes the node_modules from the build process must change their config to include debug. Or create an alias.
In any case, this is not the most practical thing.
The other popular projects transform the lib so that it can be used everywhere, with an ES version for the bundlers.
Please see https://github.com/sindresorhus/ama/issues/446#issuecomment-281014491. Using babel is the future at this point. Please modernize your build steps to use new versions of debug.
Version 4 was breaking. That's why it was a major version bump. A quick search would have shown you that @bertho-zero. Either you're mis-using ranges or you're using *, both of which are not the fault of debug.
debug didn't break with webpack; it broke with _your usage_ of webpack. There are still thousands of teams - if not more - able to bundle debug with their projects.
There is nothing actionable here.