“I’m not Catholic but as I understand this unless the Pope changed the position of what the RCC teaches on celibacy and natural marriage, he still opposes homosexual(and all other non-marital) sexual relations.”
You are correct. It is not a sin to BE a gay, only to engage in any sex acts, gay or otherwise, outside of man/woman marriage. That Church doctrine is NOT going to change, even if the Pope wanted to change it. He COULD NOT propound error on a matter of faith and morals. And there WERE Popes who WOULD have done so, IF they could have, in the Middle Ages, thus evidencing the concept of Papal Infallibility.
Is it a 'sin' to be an adulterer; iffn you only THINK about it?