Maxperson
Morkus from Orkus
And, let's be honest here, most games are going to be non-canon before the game even starts. Players will want to play this or that class/race/background that is going to be not 100% kosher. DM's are going to add towns, NPC's, dungeons, events and various other details before the first die is dropped.
That's not honest, though. The 3e Forgotten Realms campaign book talks about the countless villages, tribes and settlements, as well as the lost places of the ancients with new marvels and such being discovered each year. It also says that it describes in brief the wide and wonderful world. Other campaign guides over the editions are similar.
The PCs with their backgrounds, the towns, NPCs, dungeons and such, those are all provided for in canon, provided the DM is fleshing out the world and not altering what is specifically mentioned. Specific alterations are what constitutes a canon change, not the things you are mentioning above.