Diabetes remission is defined as HbA1c (the average of last 3 months blood glucose) below 6.5% without any diabetes medicines for at least 3 months
Yes
Diabetes reversal implies that diabetes has been totally cured and no further adjustments are required in lifestyle. That is unlikely to happen.
Even though diabetes medicines can be stopped with proper measures, but lifestyle changes are necessary to maintain remission. Reverting to an erratic lifestyle can elevate blood glucose levels and medicines may have to be restarted. So, diabetes remission is the preferred term rather than reversal or cure.