I was randomly looking at FlightAware this evening, and came across two Fedex 747-400's flying KMEM to PHNL (here is a link to one of those flights)
https://flightaware.com/live/flight/FDX948

My first thought was, "oh, they're flying 747's again?", but a quick search revealed that they are leasing Atlas Air 747's during Decembers 2017, 18, 19 thru 2021.  Thought it was interesting and a rare thing to see a Fedex 747 these days, even if it probably is in Atlas colors.

There being leased as you discovered. I came across the following discussion.

https://www.airlinepilotforums.com/fedex/109868-fedex-747-a.html

Edited December 16, 20187 yr by Wise87

Goodyear airport, not far from my home in Phoenix AZ, takes in old passenger heavies and converts them to cargo aircraft, with its long runway.  If you drive I-10 past Goodyear it makes you wonder, "Is that another International Airport?" with row upon row of old heavies lined up.  Went to an airshow there once, thousands showed up, transportation in was good but transportation out was terrible, there was never an airshow there again.  But I did get to take a fifteen minute ride in a Robinson R44 copter, the only piston five place copter I ever flew in.  We soared southeast towards Phoenix International Raceway, then over my wife's office in Avondale, then back to Goodyear slowly hovering near all those heavies being converted.  They of course looked like toys from a thousand feet up.  It was a great airshow, towards the end balloons were lit up, a colorful display.  Buckeye Airport, further west, is now the home of the big Copper State Airshow, Arizona's answer to Sun 'n Fun and Oshkosh.  It used to be at Casa Grande, way out of the city, then at Falcon Field where I took flight lessons, but too busy an airport, finally they are moving it to Buckeye.

John

https://www.copperstate.org/