First off, Wojacks ⊂ Rage faces.
Rage faces are a wider and more diverse set, that includes the original wojack (and all the wojacks by extension) so they offer more possibilities; both cringe and non-cringe. Beside, they were more often than wojacks used in comics with several pannels and characters. More wojacks are used in single pannels constituting reaction pics or criticisms of a type of people.
In a way, wojacks are the heirs to Rage Comics, but they've adapted to a web in which we consume memes more quickly and in greater amounts, hence why they're suited to smaller templates.
When cartoon network launched in the 90s, it was filled with classic cartoons, so another generation of kids remember the Flintstones, Jetsons, etc. from their childhood.