The font size was increased slightly app-wide, I think to address readability that someone raised. There are a few settings that you can adjust. The first is the "Text size option", which you'll find by scrolling down a bit on the Settings page. I think bumping it down to 0.875 will bring it back to the old font size. You may find that makes the comment text size smaller, which you can change by tapping on "Comment Customization" in Settings. There's also a text size adjustment for post titles in "Post Customizations."
That's my experience with list view though. If you use card view, I'm not sure if they were different.