No, in order for Michizure to activate and take effect is when a monster being sent from the field to the graveyard must be the last thing that happened.
Because when you tribute the Pyro-type monsters, Gaia Soul of the Combustible Collective ATK points increasing by 1000 times the number of tributed monsters through this effect, and since this monsters ATK points increasing was that very last thing that happened, Michizure can't be activated at this point.