If the WiFi card is integrated into the Logic Board, then it should be different. If, however, the WiFi card is separate from the Logic Board, then it will be the same since it has not been replaced. I don't know whether the MBAir has an integrated or separate WiFi card. There is also a chance that may Apple does reprogram the integrated WiFi card with the same MAC Address since the AASP must use a special service utility to pair the parts to the Logic Board...I have no clue what secrets this utility performs since Apple only mentions some vague BS nonsense which is probably only a half truth.
Of course this assumes a Logic Board was even replaced...perhaps it was later discovered only some other part needed to be replaced and this information was never properly conveyed to you.
There is nothing Apple or an AASP can do about a WiFi card integrated onto a Logic Board...the AASP runs this special service configuration utility when installing a replacement Logic Board on any 2018+ Mac since a 2018+ Mac will not even boot without doing so. This means the Logic Board was "configured" or paired with the existing parts.
Getting any details from Apple is next to impossible...at best you can chat with Apple support online to see if they will confirm what exact part(s) were replaced during the last repair.