amdad now that I am sitting down and have the time to answer your question without hurrying it.. Here it goes.
The Flagrow marketplace was initially created so that we can offer paid extensions eventually, for Gravure has a long-term commercial mindset. The result, Bazaar, does a bit more and solves a problem many of us faced. Our goals for Bazaar are quite ambitious and most likely will require us to maintain this extension even when Flarum itself offers marketplace functionality.
Whether the core team is interested in parts of our code has to be seen. Conceptualisation of a possible marketplace has taken place, but the definite form has not been decided on. Nevertheless the core team can expect full cooperation from us upon request and collaboration on that functionality if they wish.