I just recieved about two dozen emails spread over this moderning about people changed by user talk page at Wikimedia Commons.
Although it was more than usual, this is not new and has been happening on as long as I can remember.
Often it seems the mail is sent as soon as *I* log into the wiki (instead of when the person saves the talk page).
And this morning, well, I don't know, I got emails saying my talkpage was edited in early and mid Februari (the date, time, diff id and username is all correct, it's just that the e-mail is overly late and all at once)
For now under MW core since it's not specific to any wiki in particular (eg. Commons). Although it could be a problem in the general config WMF has.