So at some point MacVim got associated with HTML pages, and since than when I launch jupyter it defaults to opening the landing page with MacVim instead of a browser.
I have changed the "Opens with" for all HTML files, and indeed if I double click an HTML file it properly loads the page in Safari, but the Jupyter issue remains as is, which is annoying. I have noticed that the icon displayed for HTML files is still MacVim's icon, as if it's the default application.
Has anyone else experienced this? If so, any tips on how to resolve the situation?