I suspect it is the same reason why the article was written in English; it is what can most efficiently transfer the information to the widest audience because of worldwide usage.
I certainly didn't know this was year 5779 in the Hebrew calendar without looking it up.
Sometimes there are no motives. Sometimes it just becomes common usage. Someone seems to always be offended by something, so whatever you do or say, it's wrong; kind of like the PC culture.
This guy is just guilty of cultural appropriation, I suppose.
I knew an editor of a scholarly journal where historians submit manuscripts hoping to get published (because getting published is the bottom line for academics and researchers).
He was secular but he would have none of the few that wrote BCE in their manuscripts, He and his staff would review and tell authors to use the established annotation. In many cases, he and his staff prevailed but the persistence of certain authors overcame the convention and proceeded to establish their own convention.
The usurpation is still ongoing. There are still many more journals using the conventional annotation than the one slipped in to cover up the reference point.
English is prevalent and so is the BC-AD convention. Those writing in English can just as well write their calendar references in BC-AD. There is no stigma and no obligation for such writers to believe the history underlying the scriptural calendar convention.
Yes, Aaron is likely a lemming but the point is that Aaron can be swayed to do the bidding of his masters and that will most assuredly carry over into how he connects the dots on the data from the digs. That’s the point.