I really do not think that Jon Jones vs Stipe Miocic is actually supposed to happen. I think this could easily be something like a publicity stunt to get back on people's radar by Jones.
Obviously, this is very short notice for Miocic. He has no intention of taking on such a fight on such short notice. So, I find it nearly impossible to believe that this fight is actually going to take place. Honestly, I'm going to be surprised if the UFC somehow makes it happen. Miocic is not stupid, he is not in the most suitable shape right now to fight a fighter like Jones. And I think he also knows that this fight is not likely to happen. That's why he is not training very seriously as well.
Jon Jones VS Stipe Miocic really was set for the UFC 282 fight, but it was then canceled and replaced by Prochazka VS Teixeira, until the end of the year, so maybe the Jones VS Miocic fight will happen next year because I think Jon Jones had gotten the good side of Dana White and has to give him everything that he likes, but maybe you are right but not in the short notice fight I really think it was not a short notice because that fight was set on December 10, but right now I think the Jones VS Miocic will be move next year,
Kattar vs Allen, I really think that this is going to be a close fight. I am just not able to compare them. Kattar does have a height and reach advantage over his opponents in this fight. But I like the style of Allen more. If anyone asks me I think Allen is the one who has a better record in his career so far. I have not researched this fight in-depth yet. This is sort of a first impression from me about what might happen in this fight. Allen seems to have the upper hand in my opinion. He is also in a better condition than before.
There is a certain fascination to see aged UFC fighters fight. And it's encouraging to see that even though they have aged, they have not lost the skill. But at the same time, I am not very fond of these fights because they have aged and it is easy to pick up and injure.
This could be a close fight because both fighters are well-rounded both can win in stand-up and on the ground, but Calvin Kattar he has the upper hand with experience, Height, and reach, and his fight with Giga Chikadze is one of the best in his career, but for Arnold Allen that is a little bit younger than Kattar, we can see this kids speed might take the advantage, his fight with Dan Hooker is a great display that he will likely knock out Kattar if that punches connects, I will surely give my thoughts and picks maybe later,