Since bidding is done on total contract, GMs have always been allowed to decide, after the bidding is done, whether they want to go with a (P-n/a) and a large signing bonus, or spread out the money over years to absorb the costs. Many times, GMs simply post a total amount for expediency, with the full intention of opting for a signing bonus if the actually win the bidding. It usually happens in a protracted bidding scenario like Tatis, where it seems patience is wearing thin.
Sorry for the confusion, but it’s standard practice in this league and no rule has been violated.