Potentially yes, but through social engineering. Guy goes into a carrier store with your SIM card, and says “I’ve just been robbed, they took all my devices, my wallet, and my ID, but I still have my old SIM card, can you help?” And there’s a chance the people at the store might consider that enough verification to prove ownership. I dunno how common that is, but to provide some peace of mind, as long as you aren’t famous or some dignitary, you should be fine. Most theifs aren’t going to go through the hassle of stealing some randos account.
Apple only does a full replacement if the phone is broke broke. ie drowned. If you break the front and back glass, they might give you a full replacement device, but they have a metric for “same unit repair” so they might still swap over the battery to the new body. Batteries are free to replace when they get below 80%. Everything else is a charge tho