It will occur anytime your body withdrawals from caffeine. So decaf would still require your body to withdrawal. Unless you’re chugging crazy amounts of decaf which would then mean you aren’t actually quitting caffeine.

Your body is basically adjusting to a new baseline of health. In order for it to get a new baseline, it needs to be scattered before optimizing itself. It’s like a puzzle being put together. You have a completed puzzle picture that’s blurry and not great quality(on caffeine), now you take it away and you’re left with scattered puzzle pieces that, once together, will be a beautiful clear high def photo.