As TSN had made a deal with ESPN to provide some content and ESPN was a 30% partner in CTV Specialty Television, it seems likely that there was some NFL content shared. Whether or not it was simulcast probably would have depended on whether there was a hockey match going on at the time. Hockey consumes a lot of hours with its 82 match professional season that overlaps the NFL regular season.
Here's what Wikipedia has to offer regarding TSN:
en.wikipedia.org
I'm not optimistic that this matters to anyone but you. Here are some events that happened in 1998 that may be historically significant (they may have had some impact on the future):
en.wikipedia.org