It has "Live Updates" in big bold text as one of the first and most prominent lines on the page so... yes? Is that a problem?
Publications have had live-updating articles for things ongoing for years. This seems both entirely reasonable and normal, and I'm not sure what the concern or issue is.
As per submission guidelines:
> Otherwise please use the original title, unless it is misleading or linkbait; don't editorialize.
So, even if you use original title, once "Live Update" article changes, it might seem that submission did not use original title.
I read their comment as a simple “oh ok I understand now” type of clarification, not a complaint.