Being a distributed crowdsourced project, OSM strongly depends on communication channels to bring the desired level of coordination within communities. However, since there is a high level of independence and autonomy in these communities, it might lead to a situation of scattered and fragmented communication. I'm not proposing anything here, but I still want to bring this issue to attention.
Every technology used for communication (mailing lists, forums, messenger channels, IRC) might have a certain advantage over others, but the thing is that it has nothing to do with its popularity. The dominance of a certain channel within a community has historical roots and relies on a habit. An existing choice might have a justification, but that is not a reason for a particular choice. For example, why Russian-speaking community prefers forum over the mailing lists? Just because several people started using it many years ago. It's not because it's easier to search through it or because it has better message formatting features. But there is nothing wrong with it. However, there is one significant bad side.
Commonly used communication channel might get a "fork" just because several people (or even a single person) want to take over it or just because they have different habits. That's exactly what happened in Russian-speaking community starting a Telegram messenger channel. Those who don't want to use Telegram or who prefer non-real-time communication (forum or mailing list) over a real-time chat technology, become deprived of a significant part of a communication process.
Moreover, "forks" like that might be used to make certain decisions look more legitimate. For example, a certain tagging practice or a change of a Wiki page might be discussed in a limited circle of people using a new communication channel. Others, who use a different channel, stay unaware of that. While someone who participated in that discussion could later use an argument that something has been discussed and there was no objection, so let it be this way. This is a practical example of using an existing selection bias to justify something because it is easier to pick a channel of communication where a certain opinion prevails and to get an approval of any idea that correlates with that opinion (also, look up "Gerrymandering" in Wikipedia).
I am perfectly aware of the fact that there is no real approval procedure for any kind of decisions forming a structure of the OSM project. But it doesn't mean that using technicalities like that for "political" matters is something totally acceptable. I hope that someone will, at least, think about it for a minute.