This isn't true. The bootloader and boot process will be the same. This link is about the bundled Chrome (which is also what houses the entire UI/UX for the OS) becoming deprecated as the main browser for the standard Linux flavor one running through the wayland bridge of Crostini.
MY CB is eol, so chromebrew is my best alternative. Chrome is sending unique identifiers to websites soon, I don't need to run firefox because Im stuck on chrome 77, just posting for posterity