This indirectly answers my question especially with the clarification from Crawford that there's no inherent special meaning to the term "Base AC" but I'll leave this one open anyway. Though there's no source provided for the quote from Crawford and getting the same information from a more authoritative source would be ideal.

@NeutralVax I'm not entirely sure what you're getting at but I'll try to explain why that bullet is a problem. It's not that they've never seen wolves. But they'd never seen wolves like these ones. It's the GM's job to describe the world around the PCs, it is not their job to prescribe what the PCs know. So by explicitly denying the possibility that two PCs very well educated on wild creatures both magical and otherwise might know anything about these mystery wolves it makes the characters seem less cool and heroic while also denying them agency to contribute to the group storytelling.

Do you have any experience in creating NPCs using the player character classes that you can use you expand on the first part of this answer? This more or less amounts to PvP mechanically and could wind up very unfair.