There's Austral https://austral-lang.org/ for linear types, I'm not sure what is the state of the language but it has a nice tutorial about linear types.
This looks like one giant step forward in that direction. I'll be enthusiastically playing around with Austral, all while hoping these concepts can become standardised, and maybe retrofitted to popular tech by way of design patterns or language features, in the future.
Since the death of LtU I don't really know where to learn about interesting new PL work. I try to occasionally read the POPL submissions but there's nothing like HN for PL.
Maybe the Discord is the way to go. The user interface confuses the heck out of me, though. Appreciate the recommendation!