Be interesting to see, they "bought" the club for 600 million. Their dividend payments are shrinking, I think it was 20 million a year from 2016-2020 but it dropped to 11 million last year.
If they could sell the club for around a 1 or 1.5 billion, then they have doubled the value of the investment, surely they would go for it? Unless as you say it acts as collateral for their other holdings.
From purely practical terms they are highly unlikely to get CL, Spurs, Chelsea and Arsenal all look better equipped. Therefore the asset is declining in value, unless they magically learn how to run a football club, from a business point of view, their best bet is maybe to sell.