"Someone said they heard that on April 3 2021"

Hopefully that wasn't a tax preparer that you heard that from.

The earliest it will start is July 1, and that's only if IRS clears many hurdles.  

Is that anything like "according to the people who were not authorized to speak publicly"?

At this point I'm almost ready to just throw my arms up in the air and take the same approach as Sgt. Schultz.  "I know nothing!"