There are a few nuances that could come back to bite this couple. The OP says they disclosed the online marriage to the consulate, but was it disclosed to CBP when attempting to enter on the K1. Usually, when a K1 visa holder requests entry into the US, they get a question about marrying, and information regarding the terms of the K1 visa and the fact that they are not required to actually get married, or forced to be married. How did the OP's spouse respond to those questions when entering on the K1. Did they inform the CBP officer they are already married ? Would they have been allowed entry with the K1, or turned around? We shall see how this plays out. Best case, they only need to include an I130 with their AOS package. Worst case, the IO notices the date discrepancies, and digs deeper.