Sure but now there are two separate codebases for the same API. A lot of code will be duplicated between the two codebases, you'll have to maintain two sets of issues on github etc.

If it were me I would aim to merge the firefox puppeteer into chrome puppeteer but fair enough if they want to keep them separate.

EDIT: I guess it depends on how much of the code in the puppeteer chrome codebase is tightly coupled to chrome dev tools. Like if 25% of specific to chrome, then that would mean that 75% of the code can be shared between the chrome implementation and the firefox one, in that case I think merging and hiding the 25% chrome/firefox specific stuff behind an abstraction layer is the best option.