TLDR; I'm in the "please, not a web forum" camp, but I also feel like this is effectively a foregone conclusion, unfortunately.
As a maintainer of a small number of packages, I follow devel to keep up with changes affecting the distribution and occasionally chime in or find areas where I can help in some way.
I have gained an immense amount of knowledge about Fedora this way as well as a strong appreciation for the folks doing the heavy lifting.
I've tried to use discourse a bit and find it to be like every other web forum -- heavy to load and frustrating to work with. My reasons match what a number of other folks here have already said.
In particular, I don't like moving from an email discussion method where each participant can choose their own client and tools to work as they want to a web interface which is one-size-fits-all (or none, as often everyone loses something).
I'd be among those who are simply less informed and engaged in the Fedora development community if things move to a web forum. If there are a lot more gains in doing so, I wish you well in the endeavor.
Thanks,