In March 2014, the question Find the Nash equilibria for a joint project modeled as a strategic game was migrated here from MathOverflow. It was promptly answered and the OP accepted the answer.
In February 2015 (a few hours ago as I write this), an anonymous user proposed an edit that appended three more sentences (each of which was a question) to the end of the original question text.
The added questions were relevant to the original problem and might even have made sense to include in the problem when originally posted. At this time I would find it completely reasonable to ask a new question as a followup to the old question. It just seems a little weird to have a question extended in this way; I think it makes it appear as if the long-standing accepted answer ignored several parts of the question.
Possibly I'm overthinking this. As far as I know, quite possibly the edit is perfectly fine. But are there guidelines for this sort of thing?