The ONLY exception would be a redundancy for times sake and only that if it is critical to the play being made and it would be made very clear in the literature that this section was taken out for time consideration but would orient the viewer to a place that would allow them to read or view the play in its entirety.
Even the best directors and writers can not know the mind of the writer (unless it is themselves) and any change changes the play and its interpretation. Period.
This is especially important in plays by renowned playwrights such as Shakespeare. Each piece is a slice of the time in which it was created. Let us enjoy even if it is uncomfortable at times. That is what art is. (Let's hope).
A small change in the name of characters could dramatically shift the experience and take away of an audience member that could wholly misinterpret the work because of it than he might otherwise. A name change or change anyway can have a domino effect. It is not a small thing to change pieces of a play.
Hollywood is different. Unless you are an A-list writer/director, you can and should expect for 90% of you work to be altered usually or completely rewritten by another (or 10 other) screenwriters.
Even with A-list writer/directors are the producers often making constant recommendations for changes. (Depends on who and who.) Playwrights (especially contemporary ones--as well as novelists/short story writers) choose those venues so they can have full control of their creative delivery and ideas. (more so than Hollywood anyway.)