"Does AI finally enable truly humane interfaces?"
I think it does; LLMs in particular. AI also enables a ton of other things, many of them inhumane, which can make it very hard to discuss these things as people fixate on the inhumane. (Which is fair... but if you are BUILDING something, I think it's best to fixate on the humane so that you conjure THAT into being.)
I think Jef Raskin's goal with a lot of what he proposed was to connect the computer interface more directly with the user's intent. An application-oriented model really focuses so much of the organization around the software company's intent and position, something that follows us fully into (most of) today's interfaces.
A magical aspect of LLMs is that they can actually fully vertically integrate with intent. It doesn't mean every LLM interface exposes this or takes advantage of this (quite the contrary!), but it's _possible_, and it simple wasn't possible in the past.
For instance: you can create an LLM-powered piece of software that collects (and allows revision) to some overriding intent. Just literally take the user's stated intent and puts it in a slot in all following prompts. This alone will have a substantial effect on the LLMs behavior! And importantly you can ask for their intent, not just their specific goal. Maybe I want to build a shed, and I'm looking up some materials... the underlying goal can inform all kinds of things, like whether I'm looking for used or new materials, aesthetic or functional, etc.
To accomplish something with a computer we often thread together many different tools. Each of them is generally defined by their function (photo album, email client, browser-that-contains-other-things, and so on). It's up to the human to figure out how to assemble these, and at each step it's easy to lose track, to become distracted or confused, to lose track of context. And again an LLM can engage with the larger task in a way that wasn't possible before.