So, the world league and champions trophy will be replaced by some sort of home and away league that will serve as qualification for the next olympics. FIH asked nations to send bids to participate in both or either men's and women's competition and these were the nations that made the first cut:
Both men's and women's: Argentina, Australia, Belgium, England, Germany, India, Ireland, Japan, Korea, Netherlands, New Zealand, South Africa, Spain.
Only Women: China, Italy, USA
Only Men: Malaysia, Pakistan
Canada was the only top 16 men's nation that didn't bid, Malaysia also wanted to bid for women's but were rejected due to low ranking. The final cut will be down to 8 or 9 per gender and those nations will participate in the new league.
I would say that Argentina, Australia, Germany, Netherlands and England are 99% sure going to get both teams in. Also I think India and Belgium men and USA/NZ women are 99% in too. So, that would leave 1 or 2 spots for men and women available..