Yes. If you look at the shortcut content you’ll see both a creation and append option are included based on the existence of a daily draft for the current date. It is very easy for you to test by renaming any current daily draft.
You could use a URL scheme call to dictate to a new draft, or you could include Shortcuts dictation instead of the prompt to type text; but I’m not clear on what you are asking for in relation to how it would work with this particular request if you are going “into” Drafts. Perhaps a few more details of what you want to do would help?
I was trying to create this myself today and failed spectacularly. Thanks for showing me how it should be done! I’ll use this to create a podcast note log where each draft is either a podcast or an episode and subsequent notes for the same podcast is just appended.