First of all I’m glad to hear itch is still a focused service in your minds. I’d rather have itch do one or two things really well than 6 okay-ish things.
There are a few creators use virtual PDF readers or zine makers to publish essays or comics here, and it’s a damn good workaround for writeups. I reckon folks will use the blogging feature to talk about anything that doesn’t fit into any particular project or product: game design, tutorials, personal ruminations, reviews, rants, comedy, or even just travelblogging.
A good example to look at to fit all these different categories into one uniform design is probably Medium. It’s easy to work with, easy to share, and has a minimalist but extremely versatile design. It means devs who wanna pull off a #screenshotsaturday can have a place while also giving a place for longform tangents.
As for the blogging platform’s placement in profiles themselves: Notifying followers is a good first step, but it’s extremely hard to find them organically. Itch already has options to add a website link and a Twitter link in one’s profile settings menu and have them show up at the top of your creator profile. Why not add a link to a profile’s “blog” or “blog posts” there? Sounds like a plan.