Sorry, I didn't read this carefully the first time.  I'd like suggest moving away from referencing the class definitions for ASCII formats, and also explicitly say what `tablealign` actually does:
```
  - The ``astropy.io.ascii`` output formats ``latex`` and ``aastex`` accept a dictionary called ``latex_dict`` to 
    specify options for LaTeX output.  It is now possible to specify the table alignment within the
    text via the ``tablealign`` keyword.
```
Or something like that.