Another very important piece of information I would like to know is: Has Bitcoin Core software ever automatically upgraded the wallet.dat files as you updated the versions, or if you started with a 2013 wallet for example, the file stays in non-HD format? Im asking because core wants to deprecated older wallet files in (I think) the next 30 version. As of now im using Knots and im interested to know what they will do there. I think updating should be prompted to the user and optional.
i created my wallet in 2011 and i still use it today. it is still in Non-HD format. turning an older wallet into a HD wallet is a manual process.