I believe he will be the next manager, and we are going to get the occasional article to slowly make it more palatable until it happens. It will work for some people, but I doubt it would do it for the majority. As far as I am concerned, this will be a very depressing appointment, but not really unexpected.
Apart from his connections with Brailsford, Ashworth, and McClaren, perhaps INEOS think he can change the culture inside the club and benefit from some protection from the media. But managing footballers playing for country is very different from doing the same with footballers playing for club. I think he will be eaten alive and shit out by this squad before you can say "bad hire". And since it's Manchester United, any leniency from criticism his persona would bring will be very shortlived. And all of that is before his actual ability as manager and his frankly terrible football.
All in all, Southgate would be a sidegrade from the current manager, but I fully expect him to be the one to take over.