uhh spoiler alert (theory)
in the very very end of the last episode, after the credits , the russian men are in a hall / room with cells. one of them is about to open a cell but the other says "no not the american one." so they go and choose another russian man and feed him to a demogorgan that they SOMEHOW have. it doesn't look like the og demogorgans as the flesh texture and colour are different. they might have cloned or duplicated the species. as for the american that the men left in the cell,,,, i- in denial and after hours of sobbing- decided to believe that the american in he cell could be hopper okay bye