I think you are right. However I think they have broken something, if you reply to a post with it and type about 4 lines it then zooms the text right in and you then zoom out out and the box space is reduced.chrome does this as well but the beta doesn't. The beta seems to lose the cursor but that is a lesser problem.
Edit: and the text for the replied post is an incorrect font so grab the old beta whilst it is up
Edit: and the text for the replied post is an incorrect font so grab the old beta whilst it is up