Imho. It's too early to say who's "locked" for the Olympics. Instead of flat out saying that Mai, Satoko, Wakaba, and Kaori are fighting over 1 spot, let's consider the possibility of Marin (who seems to be praised as the best thing since sliced bread on this forum) not doing well on her debut Grand Prix and underperforming at Nationals. All 5 of these skaters will be fighting for the two spots. Marin may have a media push but she doesn't have as much experience compared to Satoko, for example.
The point is, we simply don't know what may happen in the coming months. Wakaba could polish her 3A. Satoko might retire. Marin could add loop combos. Even Mao could come back at full strength for all we know. It's wayyyy too early to say that some girls have 0 chance of being on the Olympic team, and that others have 100% chance. We have a whole Grand Prix series to go through and another Nationals, not to mention the many months between then and now.
On Worlds:
Mai did well, her spin levels improved to all level 4 compared to mixed level 3/level 4 at 4CC. With a new program, I think her PCS has potential to rise. Even though she skated in the 2nd group, her PCS is not too far behind Karen or Maria. Her technical score is actually better than both Kaetlyn and Gabby, second only to Evgenia (!!!). With StSq4 and different choreo, she can really be a challenger. If we take her 4CC SP and Worlds FS, we get 204.8: not shabby at all. Her SP is really what lets her down in score: she's 14th best FS but yet to crack 70 points in SP.
Wakaba

If she went clean, she could have pulled it off (65.87 SP + 129 FS (TEB) = 194.87, ahead of Ashley and enough for 5 (Mai) + 7) but the popped 2Lz let her down. I admire her guts in the last minute 2A+3T. Her PCS is actually very close to clean Mai.
Rika is injured so I wasn't expecting much. No edge violation on the 3Lz so good for her.