The time period I am talking about is actually back a few months before WrestleMania 23 in 2007. Abyss stated that his would have debuted at the Royal Rumble and had a feud with The Undertaker leading to WrestleMania 23. However, he chose to remain with TNA as he wanted to be an important part of a company rather just a number. In TNA he is looked as a "founding father" of sorts and in the WWE that wouldn't be the case, let's just point out The Great Khali as a good example of number and not an important member of the roster.
Though most people believe that the goal of all wrestlers is to make it to the WWE it is very refreshing to see such loyalty from someone who isn't just in the wrestling business just for the money. Everyone laughs at TNA and think the company is a joke and for a good reason, but if they never came around then in the last 15 years we would've had anything close to an alternative. TNA has been great for the entire wrestling profession and without talent like "The Monster" Abyss the company wouldn't have had the same success it has had over the years.