Industrial scale transportation infrastructure seems to have kept Mexico from taking on a larger manufacturing role historically, and with the anti-China near-shoring trend in the US it's probably an idea who's time has come... question remains who controls that government and for how long.

There are years old DoD presentations about northern Mexico being the next Afghanistan (geographic and cartel insurgency similarities), and now the deep state seems concerned that Trump might use the military there

If I had to take a wild ass guess as to how it's meant to work out, they lay out most of the track then the US military uses it to roll-in APCs and declare northern Mexico a province.