This can be achieved by setting up appropriate user permissions. Note that for Metapedia there are predefined user groups - Metapedia User, Metapedia Author, Metapedia Approver and Metapedia Administrator.
Among these groups Metapedia Users can only view approved terms. Metapedia Author, Approvers participate in the process of creating the draft definition, refining it and approving it. Once the term is approved, it is visible to Metapedia Users. Also if for some reason author starts revising an approved term - the changes made by the authors are not visible to Metapedia User until the revised term definition is approved.
Given this context, you should be able to manage all Metapedia activities in the same environment. You do not need to have separate Dev and Prod environment for Metapedia scenarios.