The VM runs in the host's ring 3, but the VM has virtual rings of its own. Removal of 32-bit ring 0 support including in VM guest mode could make it infeasible

The VM runs in the host's ring 3, but the VM has virtual rings of its own. Removal of 32-bit ring 0 support including in VM guest mode could make it infeasible to run 32-bit OSes in VMs with reasonable performance on the new chips. The VM hypervisor software would have to switch to emulation QEMU-style whenever the guest was running it's kernel, or revive the old scanning and patching tricks from the early days of VMware before x86 had any hardware VM support.