Yeah but that's more on the coder. Like you indirectly say, they could just as well have had a single listener for community update events, since they all share the data structure for such events (I would assume, haven't looked around too much).
And to me as a professional java coder, I will say it's just not complex. The scaffolding you mentally discard after a week of working with Java unless you're looking for something related to do the scaffolding - and then it's cool that it's all explicitly there, this has helped me countless times in my career and is one of the big strengths of such verbose languages - and beyond that and some design choices I would not have made that way related to naming and organization, there's not much code there to begin with. In modern Java you might just do this in a lambda supplied in the place where you hook the events, anyways.