The only OLC precedent for an unconfirmed Acting AG is
1) from 1866,
2) for just a week
3) under the chaotic Andrew Johnson
4) who is infamous for flouting Congress and was impeached for it,
5) before the AG was even a “department head,” b/c DOJ did not yet exist.
The Marshall Court famously struck down that provision in Marbury v. Madison (1803).
An early Congress couldn't just amend or repeal the First Amendment's text by statute. Obviously.