You can have a dealer do the work related to a TSB any time, but it's only free on Toyota's dime during the warranty period that applies to the parts involved. For an example beyond the 3/36 basic warranty, the stinky sulfur exhaust smell is covered by the 8/80 emissions warranty because the catalytic converter is part of that problem. A TSB is not a recall - it's just a known solution for a common problem.
In order for Toyota to cover it under warranty, your vehicle must exhibit the symptoms described in the TSB. You can't be doing it can't as a preventative measure just because other people have had the problem.