I'd put the chances at 50-50. Sure there are loads of Tories who think he's rubbish. There are even many that think he should go. But there is no clear replacement waiting in the wings. Gove seems to have had his chance and Patel and Raab are both from the Right so would compete over the same lane. The more centrist candidate has won every contest since at least Howard and yet there is no obvious centrist waiting.
Rishi Sunak might seem like he checks all the boxes but (for now) he is intensely loyal to Boris and his approvals will fade soon anyway.
Struggling to see how you could argue that Johnson was the most centrist candidate in the 2019 leadership contest.
Certainly not the
most centrist (that would be Stewart) but a centrist nonetheless.
Remember that Raab, McVey, Harper, Leadsom, Javid and maybe even Gove are all from his right and apart from on EU related issues Hunt has been to the right of Boris over the last 10 years. Heck, I was a swing-voter in the contest between Boris and Hunt despite having rooted for McVey, then Javid, then Raab in the opening MP rounds. I ended up #BackingBoris because I saw him as the most likely to deliver an election victory.
The idea that Boris is right-wing is almost solely due to his Brexit stance, which is ridiculous because that logic would make Galloway a secret right-winger.
Don't forget as well that Boris snapped up the support of a lot of the One Nation Group MPs which lead to his dominance of the nomination rounds. In fact the ONG is the base of his support now with most of the Right having fled him. Right-wing MPs generally supported Boris (Patel, Mogg etc) but there were a few notable ones supporting Hunt such as Mordaunt.