Echo of all Joy and Peril Returned

[Konrad Klar]

Inspired by:
Doors of Night - Effect vs Card
viewtopic.php?p=27346#p27346

Play on a resource long-event if Doors of Night is not in play. The long-event is not discarded as normal during the long-event phase. Discard Echo of All Joy and target when any play deck is exhausted or when Doors of Night comes into play. It fell upon his ears like the echo of all the joys he had ever known. -LotRVI

What if Gates of Morning is not considered to be in play and Peril Returned resolves? Would it cause discarding Echo of All Joy and its target?

My answer: yes. The phrase "when Doors of Night comes into play" could be replaced by "when Doors of Night is in play", and "when Doors of Night leaves play" (from The Will of Sauron) by "when Doors of Night is not in play" without functional changes.
Reason for which "comes into play"/"leaves play" is used rather than "is in play"/"is not in play" is that the action "discard" caused by it is momentary and it is expected that by period in which both cards (EoaJ, WoS) are in play until discarded, Doors of Night is not/is in play (respectively).

Conversely a playability condition (active condition) is expected and required to be in play both at declaration and at resolution - continuously.

[Konrad Klar]

In other words: "when Doors of Night comes into play"/"when Doors of Night leaves play" refer to termination of states "when Doors of Night is not in play"/"when Doors of Night is in play", not to the process of introducing/removing an entity called "Doors of Night".

[Bandobras Took]

Again, I think Doors of Night has not come into play; it's just considered to now be in play.

[Theo]

I'm of similar opinion as Bandobras regarding current rules, but I think changing the wording to be testing for in play or not would be reasonable and likely more sensible for how the game would feel to play.