These are not imminent changes as I read it (WD link first post). WDC is just posting that they no longer wish to expend resources in updating WD Discovery to work with new versions of desktops, whether newer macOS or Windows after June 2023. So presumably if macOS stayed at Ventura and Windows at the current build of Windows 11, there will be no loss of functionality and WD Discovery desktop sync and remote sync should still work. If future OS file system changed, it will likely break WD Discovery as we have seen this frequently with macOS updates.
**** CORRECTION, on second read, it does look like desktop network support will stop in June 2023 which means even if WD Discovery is running, there will be no mounted REMOTE drive and it will not show on the desktop, however locally mounted MCH is unaffected.
As a desktop user of this WDD feature, your best bet in replacement may be to install Tailscale which is free for personal single user (log in) use, 20 device limit.
WDDiscovery desktop notification warning end of support and utility in June 2023
As to #3, once local access is enabled, the local user name and password can be anything that is acceptable to the OS SMB authentication and can be changed as often as necessary through the wed app or alternatively directly via ip address as shown here:
