Lately, the last editor who edited an object appears to be a bot. There are a few names for bots: "matching feed 1", "waze-maint-bot", "Avsil".
IMO only human editors should appear as the last editor in the "updated" field. For example, if someone uses a script to filter edits done in the previous month, the filter includes many edits done by a bot, which is not what the user wants to see. The bot's name hides the name of the last human editor.
It is suggested that bots will not appear in the "updated" field.