No because the magnets work through a cam / lever system and they only have to move out of the way to break the flux.
One thing I did notice as I flicked thru the video with no sound, is that in the engaged position the lever was in the up position and down to release.
It really needs doing the other way so it can't get knocked down and release the part.
It is hard to mill with a mag table and you relay as much, if not more on the extra keepers to hold the work, mag tables are ideal for grinding but remember on thing, they work by having a closed path for the magnetic flux that's why you can't hold non ferrous materials and when you get down to shim thickness the holding power is very low as is the holding power of the keepers.
John S.