The DM doesn't have to actually hack or re-balance anything, unless/until they are comfortable with their ability to do so. All they have to do is stick with the content they're comfortable with, and be willing to say no when players try to go outside of that. There is no issue with short rests using the four classes and sub-classes in the Basic Rules document, after all; that's a problem that you choose to opt into.
Right now, it looks like the real problem is with players who feel entitled to use every class in the books, regardless of whether the DM is prepared for it. Or I guess the problem might be with DMs, who don't realize that they have complete control over what's available in their own games, and who may be under the mistaken impression that they should allow everything without fully understanding it first.