Does the revivify spell work on characters who have suffered stat drain death, like that from a Shadow's Strength Drain?
Revivify (PHB, p. 272):
You touch a creature that has died within the last minute. That creature returns to life with 1 hit point. This spell can’t return to life a creature that has died of old age, nor can it restore any missing body parts.
Shadow (MM, p. 269):
Strength Drain. Melee Weapon Attack: +4 to hit, reach 5 ft., one creature. Hit: 9 (2d6 + 2) necrotic damage, and the target's Strength score is reduced by 1d4. The target dies if this reduces its Strength to 0. Otherwise, the reduction lasts until the target finishes a short or long rest.
Strength Drain kills the character, then revivify brings them back to life. The only restriction on revivify is that it can't revive a character who has died of old age, and the effect of Strength Drain doesn't match that. Revivify's only other effect is to set the creature's hit points to 1; it doesn't affect any other game statistics, so the creature will still have a Strength of 0 until they take a short or long rest.
There is no general rule for "stat drain death"; creatures that kill while draining ability scores have the rules for it specified in their stat blocks. Strength Drain killing the creature it hits is part of the effect of the hit, not a persistent condition (it doesn't say "as long as the target's strength is 0, it's dead.")
Note also that a creature killed by Strength Drain may have more than one hit point when they are dead. There's no rule that says that dying causes a character's hit points to drop to zero. In that case, revivify would still set the revived character's hit points to 1.
RAW, yes. In the rules there are no set reactions to an ability score being 0, death is an additional effect from the attack itself. When revived the character will still have 0 strength, but is alive.
It is ultimately up to the DM however as they may rule that the additional text of the drain ability is itself a rule for having 0 strength.