Assume that if it's something that people will want/have to transport, then that something has been checked already. TVs are IMO not that uncommon. Probably rather uncommon on Intra-Europe flights but relatively frequent on some routes.

BTW: You can put as many "Fragile" stickers on it as you want. A baggage handler in a bad mood won't care about it whereas a diligent one will treat each and every item as if it were a newborn. That said, expect that the same applies to those transporting the TVs in bulk or on the last mile. FWIW a friend bought a flatscreen in a store, they checked the box in the store and, lo and behold, the tv has broken in two. When it comes to checking in bags there's probably little I haven't seen. From TVs to folks turning up with their things in reusable supermarket bags being surprised that the check-in agent won't accept those bags.

I'd check how the packaging will stand up against sudden shocks (e.g. the box falling/something falling onto it). I transported an iMac in the car and the packaging wasn't ideal. Standing up the box would be too tall and would create a massive bling spot. Lying on its side it was rather difficult to pack the car since you can't apply too much pressure onto the side of the box (or risk damaging the screen).