Not true...
Hosting with hostgator for 3 years now...one server at one point 42, sites, 5 or 6 peoples xf installs, live streaming, ffmpeg conversions ect ect... never got told once to upgrade anything.
Anyways...while we are all trying to give the guy good advice, remember his question is not about which host to choose, it is about how to move the site off of one host to another.