If Milone continues to outperform Gio this year there will be a strong case for firing Rizzo as his signature trade and free agent signings will have been massive failures. Of course if the Nats make the playoffs then Rizzo survives for another year regardless but as a GM it will be hard for him to overcome having his two biggest moves turn into busts.
Is Gio really his signature trade over Ramos?
Also with the drafts and the seeming involvement of the Lerners in the Werth deal I just don't see there being much of any case for him being fired, and that's not factoring in the Lerners' complacency. We're almost certainly with Rizzo for several more years.