Here's my take on this problem:
No one should ever benefit, in any way, from someone on their team committing a reportable offense.
This includes any variation of 'loss forgiven' or other negative reinforcement (reinforcement by the removal of a negative stimulus).
Allowing people to benefit from reportable offenses gives an incentive to those people to promote, encourage, or conspire to commit those offenses. This is directly contrary to the goal of the community to reduce the occurrence of those offenses.
That said, I would have no objection to increasing penalties for AFKers across the board, in ranked specifically, or even just for a teammate's 'promos'.