Option "-loadvm" cannot load VM snapshot, created from QMP API

Since QEMU-6.0.0 we have QMP snapshot-{save, load, delete} commands (commit 0f0d83a4). This works fine, when VM is running. But if we want to start VM from saved state:

/usr/bin/qemu-system-x86_64 -loadvm snap_name

QEMU returns an error: qemu-system-x86_64: This is a disk-only snapshot. Revert to it offline using qemu-img

But this is not a disk-only snapshot.