That's only a confirmation that enemies can use them. That doesn't confirm that we can ise them just yet. at least for me.
Is there any other weapon in the game that NPCs can use but not players?
Everything that NPCS do, players can do as well. (besides the little animations like sitting against a wall or something but thats not game mechanics thats just aesthetic.)
i mean if they spent the time making animations for npcs to use spears, then they'll let players do it too.
i HIGHLY doubt that npcs would be able to use spears and not players. Im like 99% sure on that, so theres a 1% chance im wrong in this.