Is it true if an areola was oval that after an areola reduction/revision it will remain oval?

Thank you for your question.  This would be false.  The shape of the natural areola can very and is often oval after breast feeding and pregnancy.  When this is re-sized during surgery, we use a round tool to create the new shape and typically try to create a round areola.  This is not impacted by the original shape of the areola.

Hi.  Typically, during surgery, we try to reshape oval areolas to a more rounder shape.  Usually they stay this way, but sometimes they can stretch out related to skin laxity or tension.  All the best,

If you operate on the nipple areolar complex you change its shape.  Ideally if you are trying to correct asymmetry, you correct the asymmetry.   If one nipple is oval is does not mean at all that it will be oval after.