@staticlifetime I have some suggestions for addition: https://kbin.social/m/linuxgaming without the underscore in name exists. And as you have linked to a general purpose Open Source community, maybe you are interested into a gaming focused one as well https://kbin.social/m/opensourcegames .
Thanks for the heads-up! It's not meant to be a list of official communities. Just a list of magazines that exist. Nothing stopping kbin users from wanting to use it, and do their own thing locally.
Instances exist for more than just to access singular communities. You can access our stuff here, and we will go to y'all as well. This is no small community either. We choose to be on kbin for a reason.