holy crap, yes, this is exactly how Twitter can monetize decentralization.
Charge the kardashian clan x amount of dollars to run a managed version of Twitter's software on kardashian.com and allow for full interoperability with other services that speak a common protocol (the w3c has a protocol. use it!)
you can also have governments and other institutional actors running the hosted software (then you can have @AOC@HOUSE.gov and @Biden@Whitehouse.gov and @x@doj.gov and @professor@mit.edu and @talkinghead@nbc.com) these all can operate as white-labeled instances of the managed Twitter service (basically, how Google Apps worked but with Twitter's software).