This might happen. Orochimaru summoning people to get answers, or even emotionally stir his opponents by summoning Izuna or Jiraiya.
umm...what about all the kunai that had blood on them.....all the blood from the rocks that it was clearly shown in the manga.Can't summon Jiraiya, he's somewhere in the ocean too deep. What truth could Izuna hold? Just Madara taking his eyes by force? IMO, they're gonna try to summon Madara and finds out that he's already alive leaving them to find him in battle with Kakashi, Guy and the Jins.
Well some people argued that previously Obito was created to give Kakashi and eye and we all know how that turned out.People needs to stop this with Izuna, he was created to give Madara EMS, nothing more. He died in a young age, what could he know. My theory is Rikudou or the sons, or Hashirama
I don't see the point in bringing back Izuna just to explain a problem then just have him unsommoned?
and Kabuto already stated to be unable to bring back Jiraiya because his corps was lost at sea.