[themacguffinman]

Windows & Linux users will still be able to use it. Most popular VPN services seem to develop their own custom desktop clients (they do this for OpenVPN); they will definitely contribute to Wireguard, but I'm not sure that they will contribute much to the desktop-specific parts of the "official" apps.

Edit: I should add that there is another cost/benefit assessment here: if Wireguard developers continue to appease Apple, Apple will continue to make life difficult for them as there will be no pressure for it to behave better.

[thw0rted]

You can't just look at the clients, you have to consider a VPN protocol holistically. Do you think that most VPN installations are going to run two different gateways side-by-side so that they can provide Protocol X for Platforms A and B, and Protocol Y for Platforms C and D? (Even worse: X for just Platform A, and Y for literally every other user.)