With the latest version of Drafts for Mac (21.2), none of the action bar items show up when the editor is active. If I select a draft in the sidebar (shifting the application focus to there), the action bar items appear, but once the editor is active again, the action bar items disappear from the touch bar.
macOS 10.15.6 on a 2018 15" Macbook Pro.
This has been fixed in the current beta and will be out in the next update. It was due to an operating system level change in the 10.15.6 update.
Good to hear! Having the action bar on the touch bar is a super handy thing to have 
Can you explain how you use the Touch Bar with the Drafts app?
As in, my personal use, or just in general, how is it implemented with in the app?
Your personal use, just kind of a ballpark idea