False news.
First of all, you should be careful using twitter because this person could be anyone claiming to be a "member of parliament". Secondly, Iran has
officially stated the cause is known but will reveal it at a later date, thus no member of parliament (even if they had access to the information) would come and reveal anything on twitter. Once the proper arrests have been done, they will come out and reveal what happened. This makes me believe either the twitter account is fake or this person is talking without much information. To be fair, he did not say Iran was attacked by UAVs in this case, he appears to be linking past events of the use of (attempts) UAVs against Iran and extrapolating. Obviously we know what happened in the RQ-170 and RQ-4 incident.
Regarding the use of UAVs, I do not think anyone is naive enough to believe UAVs could have been used to attack a facility like Natanz. That facility has multiple SHORADS including Tor-M1 protecting it. The likelihood of such things being put together internally and used to attack is practically nill.
The most obvious likelihood is the use of ground based explosives.