That mailing list is the first place you're going to hear about limited versions, new records on the label and more.
Why" going to "here not will: can we consider that the mailing list is a plan/ intention? or is it to express that it will happen very soon as in "the bomb is going to explode ?.
I would say that the first should be more plausible .However I think it is only a plan/intention for the writer and the people who have decided to subscribe, not for the others that they are not going to subscribe .
May be should we understand the sentence as " if you choose to subscribe,you will be on the mailing list and you are going to hear....... ". In this case it would become an intention / plan . Am I right ?