Reading the article it looks like the domain owner was leading wormhole cryptocurrency on a bit with counteroffers wormhole agreed to but then he backed out of. There’s probably more to the story then the headline elicits.
Bloomberg quotes a corporate lawyer who claims that the $50k price constituted a "firm counteroffer," which could be accepted, but they chose the wrong expert to ask.
Generally, for contracts between corporations and non-corporate entities, legal formalities are required to make the contract binding. This almost means a signed written agreement where the terms of the exchange have been specified.
Between corporations, or between individuals, courts have been willing to relax the requirements for formalities (meaning, not requiring signatures, or not requiring a single document laying out the agreement between the parties). But between corporations and individuals, courts have been very, very insistent on observing legal formalities, due to the extreme power differential between the parties.
It's very likely that Jump will settle this case. Even if they somehow win at trial, the domain owner can simply appeal and keep hold of the domain name for years before the appeal is resolved.
I hope he crowdfunds his legal fees if it comes to that. It would be an apt way to fire back at people claiming to defend public goods, and the negative PR would worry Jump almost more