To be honest i dont think you would get it back.... because obviously its a funny play on words that GMs just assume is bad. So i would think of a new guild name and have it ready for when you petition. That way the GM can change it to something new on the spot and you dont have to contact him 2x cause you werent ready for name change.

As far as getting it back to the old name.... obviously people have already petitioned you enough to catch GM's attention so i would avoid wasting time arguing the point its not what they think it is... and avoid a future incident.