Hi Andrew McA,
Thank you for reaching Microsoft Community.
I'm sorry to hear that you're having trouble finding the Microsoft Wireless Display Adapter V2 in stock. Microsoft has not yet made any public statements on the Microsoft Wireless Display Adapter V2's end of life. Given that we already have newer versions of adapters, it's likely that the item is momentarily out of supply or that we don't know when it will be back in stock.
As for swapping your current adapters for another product, that would depend on your specific needs and preferences. Microsoft offers a range of wireless display adapters and other accessories that may be suitable alternatives. You may want to take a look on Microsoft 4K Wireless Display Adapter - Microsoft Accessories.
For troubleshooting guide, Troubleshooting Microsoft Wireless Display Adapter - Microsoft Support.
Kind regards,
Lavenia