I'm having a flight booked for me on DL next week from RDU -BNA -RDU. The return flight is listed as DL 6252. I was looking at flightaware (checking usual gates, delays, etc.) and that flight is mostly all EWR-RDU and back, no BNA departures. I'm assuming this is something that DL changes internally closer to booking but I haven't seen this before (haven't looked every time, to be fair, but often enough so it stood out). Most likely overthinking but since someone else is booking the ticket for me, thought I'd ask here.

I haven't gotten an e-ticket yet, this is all looking at google flights and Delta.