There's no danger in fragmenting the community.
Not everyone, especially those days is willing or has enough confidence to use IRC or mailing lists. But besides that, it seems that creating new communication channels is something bad.
For me it is the exact contrary. While it doesn't necessarily mean changing the official channels, we should welcome those initiatives. This is sign of a vital project which after all want to go forward. I'd be very worried if people didn't propose things like that.
But the main thing I've been trying to say is that we know developers like certain communication channels, but this doesn't mean users should be forced to do so.
As an example, I never joined a telegram chat and don't intend to do so anytime soon.
The project should try to welcome any initiative like that, because it's a good sign and not a bad one.