You won’t need to update your theme necessarily. The updates were only minor CSS modifications. So if you’ve made adjustments to your site and you like it, then you can leave it as it is and be fine. It wasn’t a security update or anything serious like that.
Although, if you haven’t made any CSS changes, then you could update it/replace it if you wanted to.
So FYI – Upgrading or replacing it will definitely override whatever you have setup currently.