Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
This the same SKU however AAA-10726 is from SA means this customer may benefit from a price reduction when moving existing users from perpetual licensing to a subscription.
AAA-10756 Would be for an additional user eg a user added on the basis of a true up.
I believe the difference is to highlight why the pricing would be different for the same product, to the same customer. Which is to state that you are moving from SA in the first instance and you did not have SA on the 2nd SKU.