It would keep your saved world (so buildings, tamed tinos, etc), not player data though.
You can take a backup if you'd like or revert to a backup from the drop down which will retain player data but those backups only last a few weeks. So if you are constantly switching back and forth between maps within those few weeks it's doable with the backup restore feature. If it's going to be longer than the listed backups you would need to make a manual backup of your SavedArks via FTP. That folder location is: