Yes, cerainly: A rig to achieve simple posing can also do simple animation. By “simple” I mean fundamental animation like walking, waving, kicking etc.
The fact is movie-quality animation typically uses crazy-complex rigs; multiple different complex rigs in fact. Think about Spiderman: The same rig for close up body-language animation won’t work well for extreme web-slinging across a skyline. Both contexts require specific rigs to accomplish.
While animation can be incredibly complex. it can also be simplified for basic tasks.