Not really. It's a matter of where to look in the internet and which websites to look out for. There are many websites from foodies that actually travel and ate at the restaurants and can make the right recommendations. I rather trust that then some random clueless concierge staff that make recommendations based on tips from the restaurants. And from past experience, I have my fair share of incidents whereby concierge recommend the wrong restaurants that were either totally not what I want or were a ripoff. Regardless, they are still useful for doing the errant of calling and making reservation and occasionally get the hard-to-book table like what vuittons said.

p/s : most popular restaurants have also english version in their websites. And even the tokyo metro has english version. So knowing Japanese is not a must to find the way.