The phase-out of the 747 was well on the way long before the pandemic was ever a twinkle in a pangolin's eye, or wherever it came from. Those airlines that still fly them are mostly not changing their plans to either phase them out or keep flying them due to the pandemic.
As at the end of 2019, there was not a single scheduled passenger operator of the 747 anywhere in the Americas, and only two in Europe (BA and Lufthansa). Prior to the pandemic, BA announced plans to retire all 747s in 2024. They brought forward the date due to the downturn, but they're the only airline to do so for their 747 fleet as far as I can tell. Lufthansa flies the new 747-8 and is very unlikely to retire them any time soon.
There are still plenty of 747 operators in Asia: among others, Air China, Air India, Thai, Rossiya, Korean, China Airlines. Thai and China Airlines both had existing plans before the pandemic to retire their aging 747s, and the rest have all indicated that they plan to keep flying them.
I was going to say more, but let's not start a big coronavirus subthread in the middle of a neat CG thread. However, it's kind of interesting how normal it seemed to fly. Everyone is very cautious, things are sterilized, and there's not even any drink cart anymore -- it's individually-wrapped packs of food, to dampen contamination.
Not saying whether it's good or bad that things are going back to normal-ish, just that they seem to be trending that way.