That'd be pretty unlikely. The only macs in need of a refresh are the desktops, and I don't think there's ever been an instance where apple refreshed a product and then updated it again a few months later. Just sayin'.
Not only are you safe, because it was updated three months ago, but whatever kinks there could've been internally have long since been ironed out. You can pull the trigger and not feel buyers remorse on the horizon. That being said, my recommendation is to get the higher-end model and max it out (2.0 Core i7; 8GB of RAM; and 512GB of SSD), if you go to the online store for education (they don't check ID), it'll run you about $2080 ($2199 if you get it at the normal Apple Online Store for Education. Even if you don't upgrade the SSD or the processor, the 8GB RAM upgrade is an absolute must as you cannot do that later.
If I wanted to spend upwards of 2000, I might wait for a 13 rMBP to be released, but right now I just want a portable laptop with an apple logo on it for as cheap as possible (not used).