You expect Krakoa will just disappear instantly?
Hickman's leaving is only an excuse to BEGIN the downfall of this Krakoa era. His job is done because the plan is already made along with other writers who are still writing. Excalibur will continue to be written by Tini and it will has around 40-50 issues by the end of it. The relaunch will only affect a few titles written by Hickman originally but not Excalibur. Krakoa will only end in 2 to 3 years but not immediately.
Like I said Krakoa is created to 'break' dreams of younger generation who wants a world without the need to worry about dying(wars and conflicts), no shortage of food and energy, all villains turn good and you can share everything even your wife(Jean)...etc. The downfall of Krakoa is going to be ugly, controversial and it won't end well.
One reason Hickman is leaving at this stage because they want to keep his hands clean so he can write again for big future Marvel project as his reputation is still good for his setting of this Krakoa era. And it is highly possible that he will be back to write the last few issues of Krakoa like he is trying to fix this mess and give it an end a few years later. Everything is just working as planned but they just want to make you think otherwise.
For Betsy, she will remain what she currently is for a few more years but I am sure they will eventually give you the explanation for her behaviour in this Krakoa era and then she will become Psylocke again and get everything back that belongs to her. (Some people move on to the next stage by 'accepting the past' but Betsy's way to move on is by 'killing the past' so thats why she was failing.)
For Kwannon, she will end up as a villain or even worse may die again at the end of this era.
Betsy and Kwannon will be one of the biggest things by the end of Krakoa and there will be one final resolvement between the two women.