Well this is my guess what will happen,
but first, I do not think Mindark has taken the egg from Deathifier, without a deal with him.
Mindark would shoot themselves in their foot if they did. It could have nasty legal
consequences if they did, not to mention the public outcry it would cause in the community.
Logic tells me that Mindark made a deal with Deathifier.
As I understand, Feffox Mayhem is never going to happen again. It is an event to
introduce the new creature Feffox, a one time only event.
But the Feffox Nest instances will remain in the game.
Here is a hint,
https://www.planetcalypsoforum.com/forums/showthread.php?242041-Known-Issue-in-Feffox-Nests
Why fix a bug if it the event will never happen again ?
Well I think Deathifier is getting the Feffox Nest instances on Treasure Island.
The ones on Eudoria will disappear when the event is over, and one or more will
be placed on Treasure Island.
But I guess we will soon find out.