In what sense has he agreed something if no one else involved knows about it? I think the right verb here is ‘suggests’.

He made a post saying that’s the “deal”. In a way it’s a brave way to try and get a venue change. Harris would have to basically insult Fox News and their entire viewership to avoid looking like she’s walking away.

Which she should do regardless, tbh

If she can go on Fox News and score a couple points against him it’ll go very well for her though; going into the proverbial lions den and coming out the other side

No (current) Harris voters are watching Fox News right now, she only stands to gain votes if she handles herself.

Yeah putting this on Fox seems like a super risky move on the Trump campaign’s part, for not that much gain.