You won't notice a bottleneck, and it would definitely be playable.
In fact, I'd go so far as to say that every generation after the 2500k has had marginal improvements at best.
The 920 to 2600/2700k gen was a huge jump in performance, but a 3570k/Ivy Bridge was only slightly better and overclocked worse due to Intel being cheap and using crappy thermal paste.
The Haswell generation i5's were also marginally better than the last but even hotter due to them STILL using crappy TIM and having the voltage regulator on the chip itself, so it overclocks even less.
After Sandy Bridge, it has been marginal improvements + hotter/less OC room.
People tend to overestimate the effect that the CPU has on framerate. Yes, it's definitely there, but if you pack a high end GPU with even an FX 6100 bulldozer versus an i5 2500k, you'd only get like 10 less FPS even though most games would be running at like 80 FPS anyways.