It’ll be interesting to see how quickly or slowly it ends up getting attention from publishers. As far as I’m aware, most of the big academic publishers don’t even actually use LaTeX internally, they have their own custom markup languages that they convert to from your LaTeX source. Because their internal processes might not have to change much, it might not end up being such a big deal for them to accept Typst manuscripts if they’re convinced there’s a legitimate business case for it.
But before they do anything, they need to be convinced there’s a reason to do it, so academic publishing is going to be one of the last areas where Typst will be able to displace LaTeX.
The way I see this going is that first it’ll have to gain prominence in the sphere of personal use, and scenarios where you can submit a PDF (e.g. university assignments, work reports, a thesis, preprints to the Arxiv), and then people who adopt it there will have to be the ones applying pressure to publishers to support it.