No, it expires based on when it was granted not the priority date. However, different parts of the same patent can have different priority dates if they where not in the initial filing. So, some prior art after 1998 may still be relevant.
This is why a lot of patent trolls would drag their feet as long as possible in the hopes that someone would actually research, prototype and bring to market what they've "invented". These so-called submarine patents then surface to sink the company who's done all the work.
It's my understanding that the USPTO is trying to limit the ability of companies to do this though.
Wayne Westerman is one of the identified Inventors. Published papers/articles by the inventors can count against their being able to get a patent, dependent upon the character of the disclosure (did they tell a couple friends or write a widely circulated article? etc) and how long before the filing that disclosure was made.
Since this appears to be dated after the priority date, I don't think it would pose any problem, even if it were published in a professional journal.
