As usual, I believe PAP already has a person in mind long time ago which they well back as the next President.
Then up cam Ex-MP Tan Ching Bock and ex NTUC income CEO Tan Kin Lian which express their interest in running for the President seat.
I think the person PAP had in mind are not as qualified as the above 2 so to prevent another Aljunied GRC they are asking George Yeo to run.
My 2 conspiracy theory.
