One area that seems to be neglected in EA is community support for people outside of Europe/U.S.A.
It may be worth supporting wider regional groups for areas with a lower concentration of people interested in EA.
The idea is that over time people will join the groups and if they get larger, country groups can be created. At the moment people sometimes don't see a group for their country or it is abandoned and they are unable to coordinate.
This way people can indicate their interest by joining a group and when someone joins who does want to organise, they already have a network of interested people.
Here are Facebook groups for three regions I think are particularly neglected.
For completeness here are some other groups outside of Europe and North America.
I agree that Facebook groups are most likely not the ideal coordination tool, but I haven't found a platform that is as widely used without having bigger flaws.
I also agree that the impact could be negative if there are people who would build communities just because they met via Facebook but I think a lot of that depends on how it is used. One check is ensuring that people who join understand EA and have a connection to that region. Another is having filters and coaching for people do want to organise, which should reduce the chance of a negative outcome whilst making it easier for a positive one.
I think having someone involved in EA create the various focal points means that we are less likely in the future to see groups appear that have no connection to the wider EA network and research but have already become the default organisation in their area.