When a website that is often visited changes format, many people want to try out all the new features/buttons right away. If they don't work it is discouraging and annoying. If the site is a work in progress, you may want to have a disclaimer somewhere saying so to avoid getting frustrated user comments like Ron's.

Also, no matter what you say about phone numbers remaining private, most people will either not comment, or will not use a real number. It's silly to require it for commenting.