I actually did the research awhile back. The Universe toy bios that were on Hasbro.com at the time were just word-for-word abridged versions of the full-length character profiles published in the back of the three 3H Universe comic issues. At the time, Hasbro was working much closely with 3H, telling them what to write in terms of story content (e.g. - the story goes that Hasbro said to 3H "We don't care about The Wreckers. Kill the story and do Universe instead!"), so I think 3H actually wrote all of those Hasbro.com Universe toy bios.
The Universe comics were even originally planned to become an ongoing with 3H releasing several issues throughout each year. But delays pushed back the release of #1 until late in 2003 after OTFCC had already happened that year, and then #2 and #3 were pushed back to release at OTFCC 2004 itself. And then the series just died shortly after when 3H lost the Transformers license and BotCon got picked up by Fun Pub instead. Fun Pub did wrap up the Universe story with their magazine Cybertron comics and the magazine profile for BW 10th Anniversary Optimus Primal (whose separate mass retail toy bio, along with Megatron's, looks to have been written with Universe in mind, anyway), but there was originally supposed to be much more to the Universe comics than just the three issues and two script readings that we got, and released outside of just the convention too.