If this was the intent of the rules, it would be expressed in explicit, unambiguous language. They don't write contingency rules for possible future events that haven't happened this way, and if you interpret rules documents this way, then everything becomes an argument.
The implication of "the creature can only be restored to life by (x)..." is present tense. It applies to the current state of the game following the events described. The language "unattended objects catch fire" in fireball doesn't mean "unattended objects in the area of a fireball will catch fire if someone sets fire to them." it means they catch fire.
Language in rules doesn't ambiguously cater to a potential future state of the game that may not occur. It is describing the current state of the game, like the rules do in all other situations.