Version 10.0.5 was released lately. Besides other things, it brings support for newer kernel versions.
Version 10.0.7 was released: https://github.com/vmware/open-vm-tools/releases/tag/stable-10.0.7 I attempted an ebuild, but bug 565544 is still present.
Just noticed this bug was for open-vm-tools-kmod, not open-vm-tools. open-vm-tools-kmod is currently an empty package whose purpose is to remove earlier versions' installed files. It doesn't need a version bump as much as a deprecation plan (mask?). Everything is in open-vm-tools starting with 10.0.0. (Side note: I managed to fix bug 565544.)
app-emulation/open-vm-tools-10.1.0 optionally builds/installs the kernel modules now.