(This question pertains to the airspace of the United States.)
FAR 91.126 gives some general rules for operating at or near airports in Class G airspace, and FAR 91.127 gives some general rules for operating at or near airports in Class E airspace.
Section (d) of 91.126 and section (c) of 91.127 pertain specifically to operations at airports with operational control towers.
a) This seems to beg the question, are there any operational control towers located in surface-level Class E airspace or in Class G airspace?
b) Were there ever? (Counting from the September 16, 1993 "alphabet" airspace re-organization onward.)
c) If "no" to a and b, then what is a practical example of how a pilot's behavior might be altered by the need to comply with 91.126(d) or 91.127(c)? After all, it appears that generally speaking, it is not possible to get within 4 nautical miles of an airport with an operational control tower, at 2500' AGL or below, without entering Class D (or higher) airspace.