Kevin949 wrote:No, they can not, and I believe this is detailed in the deep strike rules.
It's not anywhere nearly so cut-and-dried as that. Deep Strike is silent on the issue. While the general Reserves rules have a general prohibition against start-of-turn abilities being used by units that are arriving from Reserves, Chaos Daemons icons don't carry the "must be on the table at the start of the turn" requirement that every other similar piece of equipment has always had.
The topic has been exhaustively discussed recently; please feel free to Search for it & reach your own conclusions. If it's for tournament play, consult with your
TO; Adepticon has gone with you MAY use Icons the turn they arrive.