Seems bizarre to me that the appointment of a replacement chair, should one resign, is decided on their position (in English) in the alphabet. As I understand the above:
a) Saudi Arabia has to decide whether they wish to take up the chair, and then
b) there will be an extraordinary meeting in the next few weeks to decide how to progress.
So almost impossible for the 2022 session to be held in 2022. I think their options are either hold an additional session earlier in 2023 or combine 2022 and 2023 sessions. The latter seems far more likely to me with the 2020-21 precedent (though KSA may want the kudos of hosting a session, which I'm sure they probably could manage. They do not have any nominations for consideration however)