Adesanya as he said will not be fighting for a long time. The MW division is getting too crowded with fighters that easily outrank each other now that Usman and Chimaev are moving up. Adesanya can watch who will take the belt from Sean and Dana will match that fighter with Izzy. A more marketable match is when Izzy got the belt back and Sean vs Izzy 2 will be made.
Did Adesanya really say himself he won't be fighting for a long time? I can't find anything like that in any news feed.
He's 34 and not getting any younger. Taking a long break would probably not do him much good. But it's his decision to make.
If Usman/Chimaev are to get the next title shot against Strickland, then the most obvious fight for Izzy would be against Du Plessis, currently the number 2 contender. If they didn't give him an immediate rematch, it would be weird to give him a title shot against the winner of Strickland/Chimaev (or Usman) without matching him up against someone else before then.