Welcome to the community,
first I want to say, the motto of this community is:
Only non asked questions are stupid questions, so don’t be shy to ask.
After testing, Updates are always sent out to community version first. At the community are a lot of people who have a test server and try the updates. If there are no problems they will be sent out (after a week as I remember correctly) to subscription version.
If you use proxmox you also can do a snapshot before updating, but of course a subscription helps this wonderful community and the developers of Nethserver.
Regards Michael