Nah, it's pretty clear that Gargantos is a stand-in for Shuma Gorath because they can't use him, but unless he has the same power scale and importance in the universe, it's not really Shuma Gorath. We'll just treat Gargantos as a wink for those who know, one of countless easter eggs that Marvel peppers everywhere before deciding a decade later which ones will pan out and which ones remain just a wink. That's the whole reason the entire MCU has been so successful.
If I struggled to the end of my determination, to the end of my way of life with my followers, if the result is ruin, then this ruin is inevitable. Grieve. Shed tears. But you cannot regret.