Since the newer version of WGT came out my stats in the "Stats & Equipment" are gone. Is this a mistake or did everyone loose their previous stats in the "Score History" area?
Everything from the flash version transferred over to the new version. You should not have lost anything.
Are you looking in the correct place?
If you are looking at your profile on the web (wgt.com) , everything was where it was on the flash version.
If you are looking for this information through the Launcher, click your profile pic in the upper-right corner. This will take you to a page were you can view everything.