Oh, I didn't realize it was just a hug, I could have sworn this kissed.That part at least is not a concern since there was no romance between those two. Like, at all.
That embrace at the end was clearly a "camaraderie + we're about to die" thing, not a "we both caught some feels" thing. I don't get how people can look at that and conclude that suddenly they're in love, where literally nothing else in the movie supports it.
Actually that's a lie, I do get how; a lifetime watching poorly written movies in which it's just assumed that the male and female leads will fall in love by the end (even when it makes no sense.)
I recall a similar confusion over the end of 'Pacific Rim' where basically the same thing happens . . . only it's not an "oh fuck we're dead!" hug, it's an "oh fuck we're alive!" hug. So same, but also opposite. And again; zero romance.
But even without romance I still don't like the idea of Jyn being Cassian's sister, it's just way to big of case of small universe syndrome, which is already running rampant throughout the Star Wars universe.