The F-22 will still be used. Like with the F-15 and F-16, the 22 and 35 have different roles, the 22 is big and expensive, we need a cheap, small, quick plane to replace the 16s. Although I disagree with the USAF retiring the Warthog.
I did not know they were retiring the A-10. They are in the process of upgrading them all to A-10C models, which will have glass cockpits and the ability to deliver a wider range of smart muntions.