I talked to two of my journo friends in the paddock about this on the Singaporean Grand Prix weekend. One of them hasn’t heard of any updates to the situation, but the other reported that Kimi already has worked out an agreement with Williams; just that it hasn’t been penned on paper
Unfortunately the one who kept quiet is the one with a higher strike rate on rumors; he called the Aldo Costa and Geoff Willis Mercedes move two weeks before it was announced.