Tagging the whole building as telecom=data_center isn't perfect, I'd agree.  I'd tag telecom=carrier_hotel instead, but that doesn't seem to be a thing.  My understanding is that there are lots of datacenter spaces scattered throughout the building, not limited to a specific floor, and that over time this is becoming the predominant use of the building, as is often the case with carrier hotels.  My home-city carrier hotel (Westin Building, 223928497) is generally seen as a "datacenter building" and is non-controversially tagged telecom=datacenter, despite having a small amount of non-telecom office space leased, and I modeled this off of that, but I'm not as familiar with this building and this may not transfer over.  Open to changes here!

I'm pretty sure the clli= tag does belong on the building, though, as it's a building code, not specific to an individual datacenter space.