In light of the recent changes to the question close-vote system, which comes along with a drive to change the attitude/thought process behind the votes, a "cancel hold vote" option makes a lot of sense to me.
The case for and against it has been made in the past (Can we have the ability to retract a close vote before it closes?), and apparently the conclusion was "this is not a bad idea". However, this discussion took place several years ago and the intent to implement seems to have fallen by the wayside, plus this discussion was outside the context of the recent change in language from "closed" to "on hold".
These recent changes make the cancellation of hold votes more important; the implication is that we want to emphasize to the asker that they ought to come back and edit their question to get it re-opened (that has, in fact, always been the goal). What if they do so immediately?
If I am voting to place a question "on hold", I will usually leave a comment regarding my decision and motive. Occasionally, my comment will prompt the OP to make improvements to his/her question before the 5 required votes were cast. I can and should retract my close vote if/when the OP satisfied the objections that drove me to cast the vote in the first place.
This saves reviewer time, since it is now dropped from the queue, and it reinforces to the OP that votes to hold are not a death sentence for their inquiry. That isn't to say it won't make it back on the chopping block, but if I challenge and then am mollified, I should be able to indicate that.