content: It looks like default apps that are updated in the future will either retain their current look, or just look and integrate better than before (not sure how the GTK3 apps in Mint look currently), and this will happen on Mint with Xfce, Cinnamon, and MATE desktop environments (maybe others), and any other distro that should use those packages. In-short, default apps in the future should either continue to look nice, or look nicer.