Apparently Johnsons supporters briefing against her as a way of getting at Sunak. If he Bumps her he'll have the ERG maniacs on his case really turn against him, it's ridiculous, and as you point out, selfish.
More internal tory party war maneouverings.
Was listening to a podcast at the weekend that claimed there's a dozen factions within the party.
They're now so divided that its impossible for them to govern.
Think that's what they're referring to as the extension.
Given they couldn't grasp their own situation its quite understandable that they can't grasp ours.