There have been a number of replies to this thread claiming what you're saying and not a single rule provided to back it up.
Meanwhile I've provided the rule that allows it to happen.
Simply saying 'Nuh uh!' cause you don't think it's supposed to be like that or because you heard from someone else that it was supposed to be like that isn't really going to cut it.
Many of the rules/abilities you just listed explicitly state they can only be in effect if the unit is on the battlefield. (And yes, a Dark Apostle can turn on the Remnant of the Maraviglia if he is in strategic reserves (but not if he's in a transport in strat reserves/deepstrike).