As others have mentioned, DL uses the gates typically reserved for the european carriers (BA, LH, VS etc.) in the 80s side. Usually there will be a couple aircraft that arrive at night and leave in the early morning. So it's nothing unusual on DL's part at MCO. With that said, even though MCO is not a hub and I highly doubt it will become a hub - it is a pretty big focus city. Non-stop flights to NYC (JFK/LGA), BOS, ATL every hour, DTW, MSP, CVG, MEM, SLC, RDU, and SEA (later this year) show that MCO is not just another city and gets a bit of attention.