Cover of night

So this card only works on allies already in play, and doesn't work on allies played after words.. The wording is somewhat ambiguous but led me to believe it would work on allies summoned after. It says "friendly ally have stealth for 2 turns.

I know cotc cards can't be changed :(. Oh well there goes my dreams of making a cover of night deck and blowing everyone's mind with a potentially under valued / under used card.

*you know what upon digging further I guess the wording is consistent with other abilities, for instance portal says "allies you summon". I guess abilities only apply an on summon effect unless stated otherwise?

**upon EVEN FURTHER digging I have discovered an inconsistency in wording... Outwitted reads: duration 2. Allies with cost of 5 or greater can't attack. So I played outwitted and then summoned viska the following turn; Viska can't attack. If viska can't attack and its summoned after the ability was played than cover of night should operate the same way, no?