Can. 1115 Marriages are to be celebrated in a parish where either of the contracting parties has a domicile, quasidomicile, or month long residence or, if it concerns transients, in the parish where they actually reside. With the permission of the proper ordinary or proper pastor, marriages can be celebrated elsewhere.
It could be, as you imply, a tradition of some sort.
It used to be that the bride’s family paid for the wedding and the groom’s family paid for the pre-nuptial dinner the night before.
Have those traditions also fallen by the wayside?