...One or the other or both of the cockpit crew wanted the Captain's presence, NOW. It could not have been UAS, Weather, or any of the normal suspects, imho.
Some one removed his bars (figuratively), placed them on the deck, and called for help from Captain. It is not in the nature of Pilots to do that, unless the situation is irrecoverable. Such as, an aircraft that is behaving wildly, unpredictably, and deadly.
...or you are following previous orders to be called back if the situation calls for it. Remeber we are taking about French plane with all French crew following clearly set 'power index' rules.
if PF knows that the situation is irrecoverable than CRM would require him to voice it and communicate with the PNF - the trace of such behaviour is when the plane has practically already fallen out of othe sky at 2:13:47 ie some 40 sec before impact.