BOS will very likely be a multi plane base in the future. Before the 2 years to flatten the curve happened, a 320 base there was imminent. DL was finally gearing up to take it to JB there and stake claim to being the dominant #2 carrier in that robust market. We were taking back the entire billion dollar Taj Mullin (finally) and there were plans for an eventual dedicated 6-8ish gate expansion on the other side for international. There was even some chatter about finally getting full customs in A which was the design all along, but some say the right palms weren't greased back then. Even without that, a fully operational A terminal with all the gates back provides far more flying than is necessary to justify a pilot domicile, even with a fractured and redundant fleet deployment. 320 seems more likely to be first, followed by the 220 and a small 330 base probably a year or three later.