I'm still waiting for a similar discovery to treat GERD. Having the condition, I've become a bit of a couch expert on GERD literature and it seems that everyone and their dog have a completely different opinion on what, in the end, causes it.
With a little bit of search, it's possible to find lots of papers that claim to solve the issue with some kind of novel treatment. Sometimes it's training the LES or other muscle (like in the article), sometimes it's correcting some sort of dysbiosis of the gut or the esophagus (see e.g. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6469450/), etc.
It's possible that they are all true, though, and GERD can either result from multiple different causes or from a sum of different causes. If that's the case, we would need better diagnostics to figure out what is causing each individuals problems in particular.
There are people with giant hiatal hernias and no GERD and there are people with bad GERD and no hiatal hernia. Hiatal hernia seems to at least make GERD worse, but is not the only factor and the causal link between hiatal hernia and GERD seems to run both ways (i.e. people with GERD also develop hiatal hernia over time instead of just hiatal hernia causing GERD).
Other possible explanations found in the literature are at least: small intestine bacterial overgrowth; dysbiosis of the esophagus; food intolerances; postural problems; incorrectly (for some reason) functioning LES (or other related) muscle etc.
It's possible that all of these contribute a little bit to GERD and whether you get problems depends in all of these factors in some non-trivial way.
