I have heard this a few times over the years.
My thoughts are this: Not only would this procedure provide the chance of creating a leak at the filter drier fittings, it also provides a chance to possibly not get the system fully evacuated leaving moisture in the system. ANY moisture left in the system will combine with refrigerant to create an acid that will eat a hole in the system, most likely the evaporator, from the inside out.
My conclusion is; if the system has held refrigerant for five years without an appreciable leak, it has had no possibility of moisture contamination, by the operation of changing the filter drier, you are introducing such a possibility. My mode of operation is to ALWAYS change the filter drier and thoroughly evacuate whenever the system is opened, but don't open the system unless it must be opened to make a repair.
In my way of thinking, this is one area that should be approached with the old saying; "if it ain't broke, don't fix it."
This is MY opinion.
Best of luck,