Jerry,
I contacted TDAmeritrade, and they said that this matter was between Schwab and 3rd party API developers.
I contacted Schwab, and they said that the 3rd parties can contact the Schwab developer portal at traderapi@schwab.com.
I assume that this is what you have been doing at this point. The Schwab rep had no information beyond that, with regard to dates or availability or company contacts. They had no info about any transition dates past November 2023. I guess that we wait until we hear something else... Prepare for chaos Nov 6th.