I guess Triangle is dead by now. I can't even tell whether I mind or not, or whether it would be better or worse. Not an area of the city I frequently visit anyway. It's almost exclusively designed for temporary fairs / pop industry exhibits / showcases over there, and I'm not sure that funny tower would have ever helped it.
It takes much more than a tower, or even a bunch of towers to make something appealing here. You don't get so many reasons to frequently go over the south 15th arrondissement, do you? There's a bit of student facilities around there, I think. Some buddies had lectures over the area, porte de Versailles. But to be honest, it's random.
As for the rest, I expect it to be actually built, and even more over la Défense and Masséna, cause these are more diverse and more lively.