Seen on Twitter, a first-gen iPad with two 30-pin connectors (docks).
This is not new: we have been talking about it for years. But there it indicates that the second port is working, at least for charging.
For the record, I bought the necessary part (reference 820-2535-01) in 2016 but I never received it and the seller has since gone bankrupt and no longer exists. But if you look on the disassembly ofiFixit in step 9, the connector for the second dock connector is present. We can see by comparing with the image of this post that the place is available.