I can see the value in this but I can see the horrible downsides as well. There is a bit of ongoing debate as to the "one true purpose" of MediaWiki-Vagrant, and this task comes down hard on the side of "a tool for developers who are creating code for deployment on the WMF production cluster." Even if that is ultimately decided to be the primary goal of the project, requiring all puppet config used in MW-V to be committed into the operations/pupppet.git repo seems like a death sentence for the project. The only people who can +2 in operations/puppet are members of the ops ldap group and that is not a group that is open to easy admittance (says the guy who asked once).

What I would personally really like to see is a puppet repository structure in labs, beta and mw-v that allows easy sharing of modules between the environments and easy addition of locally customized modules as well. The only project I have used that seems to meet this goal is the GitHub developed Boxen project which uses librarian-puppet to assemble a collection of Puppet modules from a manifest much like Composer, Bundler or python virtualenvs would do in those respective languages.