Because at the time they started looking (which was first reported in the Times and the Telegraph, not the tabloids), the idea was to move during the summer of 2022 so that the children could start at a new school, and so that the family would be closer to the Queen to counteract whatever influence Andrew was exerting.

We don't know exactly when the Queen was diagnosed with bone cancer, but I think it had to be no later than the end of 2021. The first sign we had that the Queen was smoothing the way for Charles's reign came in the New Year's honours when she gave Camilla the Garter.

That started the ball rolling with what will happen when Charles is king, who will live where, blah, blah, blah and the problem that Charles faced with fewer royals to fill up the same amount of homes. It was said he didn't want to leave major homes vacant lest the government exert pressure to repurpose them. He supposedly didn't want to move to Windsor, didn't like the place, he preferred Highgrove, blah, blah, blah.

So, either he changed his mind after the Queen died, or Camilla changed it for him, or he was future-faking and pulled a bait and switch. Or William knew that the plan was to try to entice Andrew to leave Royal Lodge, William was on board with it, and the media was told William would be moving into the Castle to prevent the Queen from knowing what Charles had in store for his little brother.