They gobble all year long, so definitely a form of communication. I have also had gobblers yelp, purr and putt. But back to the gobble, from what I have seen is in the social structure of the flock and other birds can distinguish one gobble from a gobbler than another. I.E. Had a group of 3 young toms I had been watching in a field daily and a single solo tom would show up (Alpha) and the other birds would leave, at times his gobble was enough to have them hightail it out of there. I have also seen when I have killed the alpha it changes up the social structure of those birds and makes the remaining toms more susceptible to calling, IMO they no longer are hearing the Alpha and are now responding to hen calls better. I have a lot more I have learned between all this as it was a big part of "learning turkeys" for me.
Attached is a favorite pic of mine pointing out the social structure of a flock.
MK M GOBL