I suppose that if Facebook refreshes their Note product to become more blog-like, there will always be some who will use it – gimmicky or not.
I'm sure that Facebook can hack together something reminiscent of Medium's blog platform, but I'd be hesitant to recommend it as an option for the privacy conscious or SMB entrepreneur.
We know that Notes are data-mined by Facebook like any other corner of its platform, but any facelift it receives won't make it a place to produce long-form content with an eye toward promoting a business. That effort and investment is best reserved for a true blogging platform designed specifically for lengthy posts – ahem Medium, WordPress, or niche plays like Ello.
Facebook Profiles are just not typically a place where lengthy content thrives. We like reasonably short posts that can be consumed quickly – so the research data suggests.
If SEO and reach that you control is important to you, then a real blog platform that sits under your control or at least on a platform designed specifically in support of that mentality is the better choice.
WordPress for example is a great spot for generating traffic with many options for various business goals. It scales with a business and is well supported. I've found WordPress to be a worthy investment for most businesses.
Ello is a great niche for the privacy minded with its ad-free experience. Supporting Markdown syntax is a great feature for long-form writing and Ello is young enough that its a great spot for a retreat-like experience. Creative types abound on Ello.
There are many blog options to pick from today, but Facebook Notes is probably something best left for mundane things that don't matter too much. A serious alternative is still a true blogging or long-form from-the-ground-up designed solution.