Hello Luca82
As the name of the parameter indicates (/VSAN/SwapThickProvisionDisabled) this is only applicable to vSAN .vswp Objects stored on vsanDatastore.
A potential way of reducing the size of .vswp on VMFS would be to apply partial/full memory reservations for VMs, though do consider this more carefully (and not just blanket apply to all VMs) if you are over-committing memory.
Bob