Google's John Mueller confirmed that although the nofollow link attribute is just a hint now, there is still no need to use the disavow link tool for links that are nofollowed. He said on Twitter "You definitely don't need to disavow nofollow links -- not before, not now."

Here are John's tweets:

Also, it doesn't change anything if you disavow nofollow links, so if you have them disavowed, that's not a problem. — 🍌 John 🍌 (@JohnMu) September 12, 2019

So the only reason to disavow links that are already nofollowed is just in case that site owner removes the nofollow from the link and you are worried you don't take notice to that change. But like he previously said, there is no harm in disavowing links that are nofollowed.

But Google said no need to disavow nofollowed links now, before, or later with this change to the nofollow link attribute.

Forum discussion at Twitter.