Parthenon,
IMO those silo doors aren't anywhere near that thick and looks to be a mere fraction of that so I don't think the silo they showed off would survive a hit from the MOP and possibly not even survive a hit from the smaller GBU-28.
We already know has the ability to reinforce buildings to withstand at least the GBU-28 (the previously most powerful conventional US bunker buster) as since in the construction of the Natanz facility.
However whether Iran's missile silos are strong enough to withstand either weapons, I don't know but IMO the silo they showed in the video wouldn't withstand either one.
Catsoo,
Except I believe the US and Israel have long thought Iran may have missile silos and likely planned accordingly, so this is likely only a surprise to the media not the military planners in either country. Therefore this public showing of them likely only confirms their suspicons they existed.