Like already explained this is not only touching complicated concepts like symbol table, execution phases and typeglobs, but might also depend on internal implementation details.

It would help to know, what you expect to happen, when a module is "refreshed".

Best in an SSCCE with a test suite, because words (and perldocs) are fuzzy.

And keep in mind that functions of a module might also have been exported to other namespaces or their reference is stored elsewhere.

Now, are those "links" to older functions expected to ...

• survive
• being disabled
• redefined

... ?

Please clarify!