No, we will not abandon Itch! Currently all our demo beta builds will be available in Itch at the same as in Steam as the release pipeline is fully automated. I should've included this in the post.
I'm not yet sure how we will handle the Itch side of things for the full release, but at least the demo will be available and always up to date in Itch. I need to study the release as I've never tried to sell anything in Itch before.