Removing an author then adding him in a revised manuscript
Removing authors and changing the author order in a revision is suspicious. There can be perfectly valid reasons for that, but it could also indicate misconduct of the corresponding author. So, asking for explanation and for confirmation from all authors that this is indeed an agreed upon change is very reasonable behaviour of the editor.

If you can provide this, there shouldn't be a problem (provided the explanation makes sense).

If you react by reinstantiating the original author list, it will appear as if you got caught in the attempt to falsify the authorship. Whether or not this will lead to a rejection is something we cannot predict. Now if you indeed were caught trying to falsify the authorship, I neither can nor want to help you.