Sony says they still don’t know when the new Sony A7rIIIa and A7rIVa cameras will be available for preorder
Techradar asked Sony about the new cameras and they got this simple answer:
We have updated the Alpha 7R III and Alpha 7R IV in response to customer needs, as we always strive to provide the best technology. The current models will still be available to purchase, in line with retail stock. We don’t yet have an on-sale date for the new model.