>>105567262like iCloud locks on iPhones? Not that I'm aware of. My airpods were thrifted (I know, ew. I sanitized the crap out of them in every way possible.) And I had no issues pairing them. I've never noticed any locking feature with their keyboards and other input devices.
I wager iCloud locks are more for things that would hold personal information (phones, computers,) to discourage theft of those. Someone steals your earbuds, worst case scenario, you just go buy a new set. Someone steals your phone, your life turns into a mass of inconvenience and annoyances, since it's probably the hub of your daily life. Not to mention personal notes you kept on it, and photos.