Finally the 8th Y-20A - number "11058" - assigned to the 4th Transport Division, 12th Air Regiment was spotted.
Quite surprisingly, there are many more (+20) already built but only eight confirmed operational.
The slogan is vague. 加油 in Chinese is very often used to cheer people on, such as exhorting athletes to run faster, to go all out in their efforts. Seen here, the slogan could mean "work harder/run faster toward a new era" or it may mean "a new era of refueling". It's a nice tease, with the true meaning up in the air.
Regardless, the efforts are underway to produce a tanker version of the Y-20.