If you would rather view this from a holistic point of view: the system really should reference cards and their abilities when the cards or abilities are “in play” (and I’ll use the term “in play” loosely here since there can be cards that are exceptions to the rule).
So, why shouldn’t Ghoulie’s effect be “active” when not in play?
I’ll jump to the scariest conclusion, if we had reference every card with its full attributes, you’d have permanent aura-like effects from all minions! Every game would have you under the influence from Grandmaster Zendo if we ever have a card that could generate Zendo “search” it. (And we do!)
Silly Thanatos, just reference things in currently in the deck!
Now you can’t win against Abyssian! Just stack your deck with the likes of Kelaino, Shadowdancer, Stygian Observer would be active under the same ruling. Did any minion die? Well now you just healed and hand buffed just because!
Ghoulie is the exception to our rule for Tribes currently, it being a Minion (primarily, first and foremost) with the nuance that it could be any other minion. Software Engineering is a fickle beast, and while our engineers do their best to keep the odd interactions working as expected, there’s other monsters to consider not bringing into light