Steps to reproduce
- emacs -Q test.tsx
- (tsx-ts-mode)
- Move point at the end of the comment at line 3
- (backward-sexp)

The expected point position after (backward-sexp) is "treesit-thing-|settings"
or at least stay inside of the comment line, however, point moves to the
beginning of "Hello".
Likewise, if you C-x C-e at the end of the comment line, it evaluates "Hello".

--- test.tsx (| is point) ---
export const App = () => {
  const greeting = "Hello"
  // treesit-thing-settings|
  return <>{greeting}</>
}
--- END test.tsx ---

It happens because tsx-ts-mode doesn't recognize comments. In
typescript-ts-base-mode, treesit-thing-settings is set to have "text" as
a thing for typescript but it's missing in tsx-ts-mode when it's set for
tsx.