Yes, this is true. If I remember correctly, Electrode is the 5th fastest Pokemon in the game (Including Deoxys forms). Cerulean Cave has the highest level Pokemon so Electrode will have the highest stats that it can. The IVs and +Speed nature only make it faster :p
EDIT: If you're looking for a good False Swiper/ catcher Pokemon then I recommend getting either a Weavile (Ranked 12th in most speed) or a Parasect as it can learn both Spore and False Swipe.