Yes, Justin Sun is really a very influential person in the crypto community.
That doesnt give him a right to manipulate like that on projects token price. Who will use trons blockchain in future, when they know that blockchain founder can force them to sell tokens low price and on trons founders exchange. He is not a monopolist on this market, but acting like he is. Devs would start to boycott tron blockchain, if they care about their project and investors.
More possible to happened if there's an issue like this developers will think twice before using this chain, there are lots of competitions and
developers needs to works with other developers in order to have a good business alongside together.
If Justin made this creating fuds there impacts that in the long run his business will be ruined.