That sounds like the exception, but ok, what happens when it is not possible?
Like you know, send a message "Dear candidate, unfortunately the talent acquisiton team did not manage to provide decline feedback because of xxxxxxx[0] , sorry."
Or "nothing"?
And in how many cases does this happen?
Like 1%, 5%, 35% or 99%?
IMHO it would be much simpler to directly write in your handbook something like:
"No decline feedback will be provided. No exceptions."
This way the candidate won't be expecting it.
[0] Examples:
my dog ate the feedback
the feedback was stored in a cabinet that got flooded
the hard disk where the feedback was stored failed before a backup was made
I have to imagine that something else in the "number of factors" matters much more than "high applicant volumes".
[1]: https://about.gitlab.com/handbook/hiring/interviewing/#rejec... > Everyone who interviews a candidate must complete a scorecard and are required to input pros and cons as well as an overall recommendation.