This is not the case and this is a dangerous myth. Chromium will still send data to Google after March. Google will still be able to track Chromium users after March. Only the sync is disabled, features like Safe Browsing, which sends websites you visit to Google, will still be enabled.
Google Chrome only supports a limited set of distributions, CPU architectures and versions. Chromium supports almost everything thanks to the hard work of hundreds of packagers.
Google Chrome also isn’t available in regular repos or as a Snap or a Flatpak, adding extra hurdles to installation and updates.
People are upset because this move severely limits the number of people and distributions that can have the full Chrome/Chromium experience and it flushes a literal decade of work by hundreds of packagers down the drain with a month’s notice.
Want the most popular browser on your new Linux distribution? Well, you better make sure to keep compatibility with RHEL or Ubuntu because otherwise you’re screwed…