I don't know, I think the fact that he might be completely washed up could be a reason, other than being stubborn, to pass on Posey. I am sure Danny has the inside info on how Posey was in Indy last year.
I also don't believe for a second that Danny will not be signing another wing. I just think he is being patient. There are still a number of better options out there, and until they are off the table, I don't blame him for not jumping at Posey.
While, this might be the roster they go into the season with, I think free agency will be continuing to play out over at least the next few weeks.
...I also wouldn't put it past Danny to make a trade sooner, rather than later to try to get a more impactful player off the bench, perhaps using JO as contract filler.
It has only been 4 days since they learned that Green was done, and sometimes this stuff takes some time to shake out.