This is a silly squabble.
MSG was a complete gut job that had to take place over many years during the off-season. MSG was nearing 40 years of age and was a dumpy arena with cracks and a odd layout. IT was renovated in the late 80's but it was a patchwork renovation that you would typically see for arenas and Stadia. Let us not forget that MSG is sitting on the most busy commuter station in America, the place was a mess.
The only thing kept in place was the outer shell and the iconic roof (that was re-done), everything else in the facility was worked on with a full new level added.
To the TV eye you just see new seats and a shiny new bowl but majority of the work was a gut job in building a new level and new internal foundations.
You can see clearly in the pictures that structural work on the concrete and the bowl levels was done, not just adding new seats and some paint:
BEFORE:

-somuchdustandsand.blogspot.com-
AFTER:

-www.sportsgrid.com-
Part of the reason for the massive gut job is that MSG Ent. had to dump as much money to get the City of its case due to pending Penn Station renovations/expansions. As well as the fact that the arena was becoming dated and no longer ahs exclusivity with Barclay's Center in Brooklyn being a competitor for events (turns out though this never materialized and Barclay's has not seen the traffic for events it anticipated). The City expects MSG to be demolished or "moved" but MSG Ent. is not having it. After $1 billion pumped in they will hold the City ransom to build them a new arena and recoup the renovation costs, a total that would likely be $2-3 billion in total. This has caused the State of NY to bark down for another solution to the City as it would be to costly to try and force MSG to move.
In the end, not calling MSG a complete rebuild, this would be like calling BC Place the same stadium after its major renovation. Consider the fact that MSG had a more through job done into re-making it versus BC Place which still has many of the same interior parts in place.
MSG and Solider Filed are both on par for complete re-builds.
** I am a big fan of the MSG roof. I wish and hope the new Ottawa arena does something similar since this new arena is supposed to be a performance hall as well.