No, he is not preventing access. However, commenting on disciplinary actions, or desired disciplinary action is not ok either.
You have been given all the advice that can be given at this point.
- GMs do NOT change the game nor do they pass on suggestions.
- Suggestions are done via the in-game suggestion menu or via the Discussion forums.
- Mailing the Accessibility team gets another set of eyes on accessibility related issues like button size in the new UI.
When you have done that, you are done. There is no more you can currently do. If you keep making more threads, submitting extra tickets, etc that only puts you at risk for spamming them.
Your thread about classic UI is a very constructive way to address it for now and is a great place to continue.
If what you want is the map, tracking, and bag buttons bigger, you can go into Options and select the Scale UI option. That lets you set the WHOLE UI to bigger so the base buttons are much larger. From there you would set up your other scaled buttons using the new interface to layer those over the upscalled UI base. Clunky, but works for now until either Blizz changes it or Addons address it.