The "XXXHDPI update" you see in modern changelogs often refers to apps fixed XXXHDPI PNG files and replacing them with vectors. This ensures that on an XXXHDPI screen, the image is mathematically calculated to be perfectly crisp, rather than relying on a pre-rendered image that might not fit the screen perfectly.
A Paradigm Shift in the Entertainment Industry in the Digital Age : A critical review paper in the Global Media Journal xxxhd updated
Using updated formats like H.265 (HEVC) allows for high-quality video playback even on slower internet connections by compressing data more effectively. The "XXXHDPI update" you see in modern changelogs