Many people that I know with upgraded weapons had reverted their weapons back to TB 9 in anticipation to these changes and come patch day, they were able to go straight to IA 6. The amount of hearts they've saved will likely allow them to go straight to IA 9 whenever that gets released. I think it's rather unfair to allow these reverts to happen, allow people the opportunity to have this advantage for a week and then take it away from everyone else who may not have been able to get there. At this point, its better to leave it in as it is.
But hey its NCSoft ¯\_(ツ)_/¯