Because it does not mean just a get together.
is there a parallel to a non Lubavitcher? Is it like a kumzits? With less singing and more dvar torah or something? A chaburah?
Here’s a line from the book: they made it (rubashkins torah emails) into a small weekly shiur which consisted in part of learning the dvar Torah I sent that week after which they would farbreng a bit.
What did they do at the farbregen do you think?