Let me ask you guys something -- if he reworded the announcement of the new forum to something that more clearly reflected that he meant 'newsletter authors and financial contributors' instead of 'supporters', would that help?

Changing the wording would ONLY work if you're willing to let go of negative assumptions that there was an intent to be devisive in an elitist way. I can't speak for him, but when I re-read the announcement and I mentally substitute the word "supporter" for "newsletter authors and financial contributors", then I, for one, wouldn't feel excluded.