I'm not sure the "Discard" word correlates with "draft". At least not for me, it just means "discard"
I think a good way would be to combine a banner or top bar on top of the page, letting the user know whatever message you want them to know. In this case, that the page is in a draft status.
A banner displays an important, succinct message, and provides actions
for users to address (or dismiss the banner). It requires a user
action to be dismissed.
Banners should be displayed at the top of the screen, below a top app
bar. They’re persistent and nonmodal, allowing the user to either
ignore them or interact with them at any time. Only one banner should
be shown at a time.
Note: Material does a distinction between banners and top bars because they call top bar to a mobile element. However, some people calls this element a top bad because of its placement, and to diferentiate it from the typical advertisement banners
In the example above, you can see how it can be easily adapted to your existing UI,
You can also combine this notification with a color based message. You could adapt common alerts color coding (for example: red if you're about to delete the post, yellow if it's a draft, green if it's succesfully published, blue if you're editing an existing post), or create a custom color system based on your UI guidelines . You could use this for the bar or use the current button as indicator. In this case, you could use conditional labels based on the type of content