That thread is all over the place, lol. If the engine was idling at 1500 RPM after warming up then something is wrong with the idle control system, or something else beside the oil & filter is causing it. Then he did an oil change and the idle went down to 750 RPM when warm and that's what it should be. So he's thinking the oil filter caused the idle to go from what it shouldn't be to what it should be ... what a mess of confusion going on in that thread.
Definitely that’s not normal. Mine idles at around 550rpm. 750rpm is a high idle.