> The bug is reproducible for clojure-ts-mode. If "sexp" thing is defined for
> tree-sitter mode, forward-sexp-function is set to treesit-forward-sexp
> (https://git.savannah.gnu.org/cgit/emacs.git/tree/lisp/treesit.el?h=emacs-30#n3147)
>
> This setting triggers condition in the up-list function
> (https://git.savannah.gnu.org/cgit/emacs.git/tree/lisp/emacs-lisp/lisp.el?h=emacs-30#n258)
>
> If point is outside of a top-level sexp, up-list function calls
> forward-list until point position reaches the bottom of the buffer.
>
> Expected behavior: point stays at the end of sexp and message "At the top
> level" is shown in the echo area.
>
> On master branch this issue can be fixed by setting up-list-function to
> treesit-up-list, but on emacs-30 up-list-function doesn't exist.

Thanks for the bug report.  This can be fixed for Emacs 31 (i.e. current
master) by such patch.  Also please note that treesit-transpose-sexps
is working again on Emacs 31.

> Would it be possible to fix the issue in the next bugfix release (if it's
> planned)?

You could try to convince our maintainers to consider backporting the fix
from master to the release branch.