Discussions is a valid suggestion, to be sure, and I sorta asked for it with the SO parallel. 
That said, I’m going to stick with the GitHub Issues plan for now. Even with the forum here we have still have basic questions showing up in GitHub Issues already—I don’t see that going away if we migrate the forum to Discussions.
The reality is that users don’t really care which type of content in which channel, people are going to ask for help on any and every channel they discover that is easy for them to post to. Rather than trying to force certain content into certain channels (and then having to transfer content from one to the other, which is kinda clunky), I would rather see if we can just manage all content in one channel (or a minimal number—we still have have Discord and of course Twitter). I think we can do this with labels in GitHub issues.
Another consideration is that we have automation internally to measure our response time to incoming GitHub Issues. We could extend that to Discussions, but folding into Issues is lower-hanging fruit for bringing these conversations into our visibility framework.