Lt. Dan was redeemed when he lost his legs and became a cripple. It was a film about heroism among the downtrodden. Today there would be a gay guy or girl and a trans person in the group.
You’re right. If such a movie were made today, there would have to be a homosexual character.
Given that Forrest was in the military, perhaps one of his army colleagues would have been a homosexual. And given the times, there would have been sympathy since open homosexuality was not permitted in the military then.