We don't change a building to "under construction" status until the framework of the building starts to rise.
I can't give you an exact reason why, that is just how it is done.
Once they start erecting the steel or pouring concrete columns, let me know and I will update the building's profile. If there is anything else that can be added to the building's diagram page, let me know via PM and I will add it. If there are any other changes you want to see, PM me. Please include sources, as well. For status changes, simple photos will do, but any claims about the building (such as use or height) require some sort of secondary source, like a press release or news article.
I don't follow this discussion on a regular basis so if you post it here I will probably miss it.