I'll add that the original "selling" point of Svbtle was its "drafts first" approach (that I really appreciate).
There's also a few references in the announcement post today mentioning writers' identity (free custom domain support, full name on everything) that could appeal to some people turned off by Medium's "nice article you just read now here's something else by someone completely different" approach.
Basically, what I see today is a side project growing up. Hard to see that as a bad thing.