I don't work for VMware and have no idea of their timetable for official support for Linux distros.
As for the XP VM guest 3D problem, it looks like it was also broken even with 15.5.7 on Ubuntu 18.04. The 3D problem is not exhibited in Windows 10 or Windows 8.1 VMs. The XP 3D problem also does not appear on a Windows 10 host. Anyway the eventual workaround that I got to try is to use the nouveau driver instead of the Nvidia proprietary. So it is hard to say where exactly the root cause(s) of the problem lies.
Yes, VMware Workstation will build the vmmon and vmnet automatically. But if you upgrade the kernel on an officially supported distro/version (for example Ubuntu 18.04 but you upgraded the kernel to some newer version), it is possible that the vmmon/vmnet build will then fail. So it is really more about the kernel version rather than the distro/version. That is why the mkubecek's Github repository would be of use; although personally I haven't had the need to use it.
If I am not mistaken, the original intent of that Github repository was to allow older versions of VMware Workstation/Player that were no longer supported by VMware to be able to build vmmon/vmnet with newer Linux kernel version that might be supported in a newer Workstation/Player version (e.g. get Workstation 14.x to work with a Workstation 16.x supported kernel version on a Linux distro host). But there are some posts here who are able to get the right source to get an existing supported Workstation/Player version (such as the current 16.x) to work with even newer versions of Linux kernels.
