I'm not looking into how German-Austria might be allowed to unite with Germany or if the Sudetenland and South Tyrol would be included, that's all been discussed before. Rather, these specific details:
1. Does Austria accede as a single state, a "Free State of Austria", or do the German-majority Cisleithanian provinces do so independently?
2. If Austria does accede as a single state, does its name remain Österreich, thereby creating a "reich-within-a-reich" scenario? The Nazi government referred to Austria as Ostmark following Anschluss, but so far as I can tell this was a neologism designed to downplay the country's history as an independent realm upon its incorporation into the unitary Nazi state.
3. This isn't likely, but just for fun, might Vienna become a co-official capital of the Republic with Berlin? Perhaps the Reichstag alternates sessions between the two cities, like the Rhode Island General Assembly did until 1899 between Providence and Newport.