I see there's a branch for the classic version of Questie, but I'm unable to get it to show up once I launch my game. Is this intended?

Most likely reason is the addon folder name being wrong, it should be called "Questie" not "QuestieClassic"

Be warned though, it really is a very early test build, most things are missing including objective notes

Thanks for the response, renaming the folder to "Questie" did the trick. I appreciate the work you do!

This was recently changed to make it easier during development, you don't need to rename the folder anymore it should stay "QuestieDev-QuestieClassic"