I am only guessing here but probably because his feud with Dean Malenko would start to take shape soon after. He would beat Dean at Uncensored the next month when Malenko goes "home".
Then, two months later, the famous cruiser battle royale would take place with the peak of Jericho's charisma shining through.
When I think of Jericho in '98, I think of the cruiser battle royale and Dean Malenko... not the cruisers he dropped on his way to feuding with Malenko. I am not saying this is right, just giving a possible explanation.
Now, that I have the VHS-to-DVD capability, I may have to compile all of the 1998 PPV matches worth mentioning onto a few comps.