Is this the way they look right now? Because they kind of look like hosta, but I would think they would not be so lush yet -- just new spring shoots starting to grow if at all. Maybe it's warmer in NYC urban pocket.
For Grep - Hosta is a very commonly used, not to say over used border plant, because it grows well in shade and is very easy. Whoever planted those picked the most boring one. Even if you are going to just plant a row of hostas there's lots more interesting ones.
This pic is from last summer. The shoots are starting to sprout again. I don't know much about plants but I do agree, they are boring. They even circle around a big oak in the middle of the yard. Hopefully I can replace them with something more interesting.
You certainly could, but since they do seem to be growing well, you might save some, but replace some with other stuff for a mixed border. Hostas do well with ferns, lenten roses, and bleeding hearts, which also like shade: