I think the scenario for pasting formula is the same as for pasting values: paste what was there at the time of copying. Is there a situation where this doesn't make sense? I'd be fine with it being kinda-wrong in situations like the original cells referred to another cell but now there's been a new row inserted and those cells are elsewhere and the clipboard hasn't updated. That's what I would expect a copy to do. Excel allows references to cells in other spreadsheets and if you edit the other spreadsheet, then the references in your first spreadsheet don't update to reflect that, so the clipboard would just act like another spreadsheet.

Edit: the better way to say this is that "copy (do something) paste" should always act the same as "copy, paste on a new blank spreadsheet, (do something) and then copy and paste that onto the original spreadsheet".