They have been starting to retire the DC-10's as of July of 2020 and replace them with the Pegasus KC-46 (767)-those have had some issues let's say

Quite possibruh this is a staged event for retirement as some of these AC's are up to 40 years old.

The Air Force Should Refrain from Retiring These 5 'Old' Aircraft

KC-10 Extender

Current Fleet: 59 KC-10s

Projected Savings: $2.0 billion if retired by 2022

Role: The KC-10 is a DC-10 airliner converted into an aerial refueling tanker and cargo plane with nearly twice the capacity of older KC-135 tankers in Air Force service. The KC-10 is already set to be replaced entirely by new KC-46s in 2024.

Does it leave a gap? No, as the KC-135 and KC-46 Pegasus do the same job. However, it could cause a short-term shortfall in aerial-refueling capacity, and the KC-46 has suffered infamous setbacks and delays.