Short: If they are random, they are random, otherwise not !
Long:
The spell does not "make" a new commander from the unit, it simply sets the commander flag. If the unit has magical abilities depends solely on it's type ID, eg. #771 for a "Tartarian Cyclops", which has A2 E3 as soon as he is a commander. If the unit type says "random skills", the unit gets a random skill upon becoming a commander. (Or is it pre-rolled already?)
A