Hamlet is a good example here: there are of course 3 primary sources (1st "bad" Quarto, 2nd Quarto, 1st Folio), and every editor's opinions are different, so any edition by an editor who has been dead for less than 70 years, or any new edition published in the US after 1923, cannot be legally copied.
But editorial work on Shakespeare is much more than deciding whether to choose between "this too too solid flesh" or "this too too sullied flesh." It includes annotations, variants, an introduction, etc. Most texts of
Hamlet today silently conflate the 2nd Quarto and 1st Folio, though the Arden publishes these separately and the 1st Quarto as well. For performing purposes, however, a director is free to use whichever text he/she wants, and that generally includes making cuts - since it's rare to see the full text performed on stage.