In an agile environment there is no such thing as “scope creep”. There are only better ideas.
Amen, amen, amen.
He hasn’t expanded on that tweet in a blog post (afaik); but really what more is there to be said? I suppose saying it gives those who don’t know what it means the opportunity to ask “what does that mean?” which could then be the subject of a blog post. But this is just words. That tweet expresses such an important idea.