Use of "may need to" when you actually need to

Software documentation is usually written by someone following a normal or good path through the setup. Saying, "you may need to do this" is essentially a callout to known issues or problems that are extremely likely. But since the author is not going to exhaust all possibilities they just stick "may" into the sentence to cover their bases.

To attempt speaking directly to your example, the person writing the documentation doesn't actually know that such a configuration exists or that you in particular need to update or that it wasn't already updated and that's why you happen to be moving the job to another folder. And they don't need to worry about those things — instead they say "may" and write out the most common scenario.

More anecdotally, I personally do this all the time when writing documentation for various install procedures. I know my audience will be someone with a similar expertise to myself and all I am really trying to accomplish is sticking a relevant problem solving thought in their head in the event something goes wrong.

Also, you'd be surprised at how many things suddenly change in technology. We kind of get used to never saying "always" or "you must do X."

Use of may does not entail that there are situations where you're not required to update configuration. It does, however, implicate so. See Wikipedia entry on Implicatures. Grice's paper cited in the Wikipedia entry is posted online.

If you say "it is possible that X". It entails that there is a non-zero probability that X is true. It implicates that there is a non-zero probability that X is false.

Common use of "imply" usually means "entail", but is often used to mean "implicate".