"I have my doubts about whether this is interest"

It will be specifically stated. And an Account Transcript would list it separately.

"No one who filed by April 15 last year was paid interest if they received their refund by Memorial Day."

https://www.irs.gov/newsroom/coronavirus-tax-relief-2019-tax-refund-interest

"Nearly 14 million individual taxpayers who filed their 2019 federal income tax returns on time and received refunds will receive interest on the refunds."

It's interesting that you post updates from IRS, which are appreciated in the community, but it seems convenient to have selective belief on a subject you disagree with, as if only parts are fake news to you.

If you subscribe to these newsletters, you get the updates. These things develop over time.