Many thanks to Paul Evans (W4/VP9KF) who notes that FCC Notice of Proposed Rulemaking–MD Docket no. 20-270–outlines a new fee structure for several radio services including the amateur radio service.
If I understand correctly, a fee would be collected when an FCC employee would need hands-on time to process an application. This would include all new amateur radio applications, license upgrades, and vanity call sign applications.
It appears many routine licence services that could be handled entirely through the FCC ULS system/website without human intervention might remain no-cost.
At least, this is the way I read the information from this FCC Notice of Proposed Rulemaking. Please correct me if I’m wrong.
Most of the amateur radio changes are outlined under “personal licenses” staring at section 24.
To be clear, this is a proposal open for comment. These fees have not yet been adopted. I expect the ARRL will have a response.