Well, I note that Sun's tweet is factually incorrect about the blockchain and token, as they aren't proprietary to Steemit, Inc., but open source code and tokens owned by stakeholders themselves.

I believe hosting the blockchain is done via nodes, and MIRA seems to have done much to reduce the cost of hosting nodes. I'm not a coder or dev, and my understanding of such matters is foggy at best.

Regardless of inaccuracies in the tweet, Tron seems to believe it has purchased control of the blockchain and Steem token, which it's massive stake of Steem (roughly 1/3 of extant stake) does seem to grant control of witnesses, and thus governance of the code and blockchain.

Thanks!