Bannon is clearly threatening to impeach Garland if Garland indicts Trump and Republicans win control of congress in 2022. Again though, who cares as there is a 0% chance of Garland being convicted.Such an empty threat, as if Garland would stay as AG in a second Trump term. He’d either resign or ask to resign which he would then do.
If Republicans win the House I think you can expect numerous impeachments of Biden and various cabinet members.