Sure, I can elaborate. Most messaging systems which bridge to email will work more or less like a mailing list. The To address might be something like noreply@github.com or it might just not be present. That is, unless you are mentioned: in that case, your email address is added to To: (or, depending on the system, Cc:). Pretty much all email clients will differentiate these two cases without requiring any explicit filters. On GMail for example, I believe the rule is that it adds a › symbol if one or more of the messages in the thread was historically addressed to you, or » if one of the messages in the thread which are currently in your inbox are addressed to you. On Apple iOS mail, the message will have a small TO in a box right before the subject line, and so on. Additionally, the notifications you receive may differ depending on how you have your mail client configured, which is very useful, assuming that one particular piece of software isn’t sending everything To you.
This has been figured out dating back the the old phpbb days and the web forums of the 1990s, so it’s unfortunate that Discourse has dropped the ball on this given the sheer volume of prior art that exists to evaluate. But hopefully we can get them to enhance this somehow.