No sir, 9 para SF also has these (they came with Galil SARs) now mostly used as an improvised optic on Pika MGs and sometimes AKs.That M21 sight is used by only SG and the production has been stoppped many years before.
I believe 4 para SF also have these.
SFF got these with their batch 0 tavor tar 21 rifles.
With that said, SG maintains extremely high level of OPSEC at any time, except for a few pics that were taken by media guys during their CI/CT phase in Insurgency affected areas(mostly kashmir)