The new 21st edition of the Bluebook became available Summer 2020.
One big change is the way federal statutory code sections are cited. If you are citing to the current U.S. Code, you do not have to include a year. This is true when you are citing the official or unofficial code. HOWEVER, if you are citing to the code from Lexis or Westlaw, you must still include the currency information according to Rule 12.5.
See the Summary of Changes, below.