Iran's larger end goal with concealing and fabricating weapons research in these sights is to simply "prep" the facilities for visitation by IAEA members. Iran has gotten to the understanding that if it at least entertains IAEA members at it's nuclear facilities, this would act as a deterrent from Israeli military strikes on the sights. Iran essentially wants to use the visitation by IAEA officials as unsuspecting Human Shields. I could even see Iran ENCOURAGING IAEA officials to stay inside Iran for as long as possible because of this underlying human shielding effort. Military analysts should know, the ONLY reason they are covering up data right now, is to prep the area for inviting human shields.
Netanyahu: Most of Americans see eye to eye with Israel on dangers of Iran deal (Haaretz)
from the article: Iran suspected of increasing covert nuclear work at military site