Who's betting on a third level up move for SV? And only a third?
Slightly tangential but I noticed that as of Platinum Caterpie, Metapod, Weedle, Kakuna, Wurmple, Cascoon, and Silcoon - all of whom learn fewer than 4 moves in previous generations - had their movesets "filled in". The cocoons got Iron Defence and Bug Bite from tutoring while the bugs got Snore. Magikarp also got access to Bounce as a fourth move alongside Tackle, Splash, and Flail; Combee, Burmy, and Kricketot all got Bug Bite by level and a bunch of tutor moves each; and Beldum got four new moves via tutoring.
This idea of making sure that all Pokemon* should be able to learn, at minimum, four moves seems to have persisted because even Tynamo, which cannot use TMs in Gen V (and nothing by tutoring in its debut game), gets four moves on its own; the same is true of later Pokemon with minimal movesets like Spewpa and Blipbug. The exception to this rule is Cosmog and Cosmoem iirc.
*Aside from the obvious exceptions