Unfortunately, the Guardians building is 130 feet tall, so 50 foot cypresses wouldn't even reach halfway up.
I would think that if there was a longer-term plan to disguise this building by putting something new in front of it one of our trusted voices on this site would have spoke to that plan instead of echoing the frustration of it being as bad as it is. No one's even hinted at that, so it seems overly giving to presume.
The outside of the building is being covered with panels in a consistent paint scheme. A lame, blue and green one, but a paint scheme nonetheless. This IS the final product. If they improve it, more power to them, but nothing they're doing now is intentionally temporary.