Well, yeah. It also matters what her relationship with her husband was in the period between 1990 and her death, whether her death impacted his relationship with his daughter, etc. The story was ultimately about family, including most prominently Wayne's immediate and extended family, so resolution for his most prominent and important family member in the story would have been nice.
Also if we assume she was 30 in 1980, which seems about right (especially considering how youthful and attractive she still was in 1990

), that means she died before reaching 65. That's not young but it's not really "old people die

" age either.
It's not a huge deal, I still like the finale and think this was the best of the three seasons. Just saying it would have been nice to have the gap in the narrative filled in there, and it would have been easy to do as well.