Obviously, it took an unusual series of events for these 5 players from three different recruiting classes to all go pro in the same year.
I think all the Final Four teams had at least four future WNBA draftees on them. They just had a more even distribution of draft years.
Baylor had Brown and Jackson drafted in 2019. Cox is a likely 2020 lottery pick. I think Richards and Smith will be drafted as well (not sure about Landrum).
Oregon had Cazorla drafted in 2019. Ionescu is the probable #1 pick in 2020. Sabally and Hebard will likely be drafted as well.
UConn had Samuelson and Collier drafted in 2019. Dangerfield is a likely 2020 1st rounder. Williams, Walker, and Nelson-Ododa are all sure to be drafted, too.
2018 UConn actually had 5 1st round picks among their juniors and seniors. Compare to 2019 Notre Dame having 3 1st round picks and 2 2nd round picks among its junior and seniors.
You basically can't win a championship these days without 4 or 5 future WNBA players. 2018 ND probably had about the minimum - 2 1st round picks, 2 2nd round picks, and 2 undrafted in their six player rotation.
So yes, it is remarkable that ND had all 5 starters drafted and didn't win the title. But I don't think they had a signficant talent advantage over the other Final Four squads.