Yes, but this is not my experience. For example, say I'm travelling on a Sunday and expect to get to the hotel at 5pm. I might receive my digital key at 10 AM, Even though it is not check in time, the room is ready and they've released the key. Then, later, but still before I get to the hotel, I receive a new digital key, with the notification that they've given me a new room. This has happened more than once in the past year (usually I am already upgraded when I do OLCI).

I guess it all varies based on the property you are staying at...