-Player A on Character A-1 Kills Player B on Character B-1
It is given that Character B-1 may not reengage Character A-1 within two hours of the original time of death. That one's obvious.
It is also give that if:
-Player A switches to Character A-2
Then
-Player B may only engage A-2 if there's no obvious connection between Character A-1 and Character A-2.
It is also given that if:
-Player A stays on Character A-1 and player B switches to Character B-2
Then
-Regardless of whether or not B-1- and B-2 are linked, Player B may not re-engage Character A-1 (or obviously linked A characters) within 2 hours of B's initial death. Period. End of story. Player A may then report player B of suspected re-engaging.
Basically, if Player A stays on the same character he did the killing on, or a visibly linked character, then the rules were as they always have been. Player B may not re-engage Player A unless Player A has switched to a character not visibly linked. The only time the rules change would be if Player A changes to a character that isn't visibly related.