Given how heavily certain group lobbied to prevent the government from issuing just a temporary waiver after Hurricane Maria, I wouldn't bet on this happening anytime soon.
Democrats support the Jones Act because their core constituents do. Republicans have a complicated history with lobbying for Puerto Rican issues. So neither party has an incentive to fix it, and neither party sees Puerto Evans as constituents.
I bet 99% of their constituents don't even know what the Jones act is or would be perfectly willing to change it.
That's a bold claim. On what are you basing the assumption that many or most Democrats would be willing to change the Jones Act, if they knew what it was?
It's not particularly bold to assume that convincing Democratic voters to repeal an obscure law that the AFL-CIO vehemently supports is an uphill battle.
There is literally zero evidence that members of AFL-CIO unions oppose the AFL-CIO's persistent lobbying in favor of the Jones Act. There's plenty of evidence to the contrary, namely (1) the fact that it serves their own interests, and (2) the fact that there has been zero opposition to it over the last century that the AFL-CIO has supported it (in contrast to the example you site).
The Jones Act requires Puerto Rico to use only a small number of US merchants for shipping to and from the mainland. Because those few merchants have an oligopoly, they're much more expensive than any of the alternatives. This raises the cost of everything that's not produced on the island itself, which directly or indirectly inflates all prices on the island. As a result, the island's exports become prohibitively expensive as well, which means that they can't really afford to buy much, but they also can't produce anything that's cheap enough for other places to want to purchase them.
While the Jones Act technically applies to all states, Puerto Rico and Hawaii are uniquely affected by it due to their inability to ship anything by ground transit, since they're islands. (Hawaii also suffers due to the act, though they have representation in Congress that has enabled them to secure waivers at times and other exemptions to mitigate the impact. Puerto Rico does not.). Air shipments are not an option - air is always orders of magnitude more expensive than either ground or sea - shipping over water is always the cheapest.