He did die when 10 tails was extracted from him to create kaguya. That was when black zetsu betrayed him and stabbed his arm into madara. After that, he started to expand rapidly because his body could not intake the charka that was given to him.
Madara Uchiha met his demise in “Naruto Shippuden” episode 474. In the said chapter, Hashirama Senju proposed a treaty to Madara Uchiha which allegedly caused his death, after losing the tailed beast and evil statue.
But all that probably wouldn’t fit in the Boruto Anime. Madara is dead and the only way for him to reappear is through Edo tensei or Rinne Rebirth. So only Orochimaru, Kabuto and Sasuke have the knowledge and abilities to revive him.