The business case reason Russia would have a central orchestrator in a Russian data center is that they want centralized control. They are unlikely to delegate control of the information sphere to another, or allow a huge random mass of uncoordinated individuals just “post positive stuff about Russia”.

Putin seems to very much like control, and I doubt he would delegate control over foreign propaganda to agents outside Russia.

This is especially true if you want to spread a lie. Lies have to be coordinate, the truth does not.