The saber calling to her doesn't HAVE to be explained by her being a Skywalker, though, and such an explanation wouldn't actually track with the things that we know about her relative to the characters she interacts with and the timing of certain important events relative to her age in TFA and her age when she was abandoned on Jakku.
This literally makes zero sense. Not one thing that happens in the movie suggest any reason why she can't be a Skywalker. Rey is between 19 and 21, she is dropped off as a child. The age in which Kylo falls to the Dark Side is never stated, but he is close to 30, so it could have been over a rather large period if time. So even if Rey isn't little during the attack (and I still totally think she is), Luke fears the same for his daughter/niece, and decides to hide her as far away as he can. The same way he and his sister were hidden. He blocks her memories and does not drop her off himself, as it would mean he knows where she is.
In TFA we see the manipulation of the mind and memory by the Force (Force visions and the battle of minds between Rey and Kylo) and Rey sees herself among the Skywalkers in her own visions. You do realize that happens right?
She arrives in the memories of Luke, Vader, Kylo and herself. No one else. By the way, my money on the massacre scene not being from her or Kylo's POV, but her mothers, who we haven't met yet. Would make sense as it would be:
1. A vision of Vader.
2. A vision of Luke.
3. A vision of her mother (being killed by Kylo).
4. A vision of herself.
5. A vision of Kylo from the future.
The funniest thing about this argument is that it is actually painfully obvious for many simple reasons outside of the actual narrative.
1. They emphasis Rey being dropped off on Jakku. She wasn't born there, her parents didn't stay with her. So what of her history before Jakku? Why make a point of it, if it doesn't matter?
2. They never show her parents. They show her being dropped off, and specifically show a scene where the ship and her parents are unidentifiable. Why do that? Why, if it isn't someone we already know?
3. They emphasis her parentage in the trailers and the Skywalker bloodline.
Personally, I think the original intention was for it to be Han and Leia. But at some point, they changed it to Luke for one reason or another. The deleted scenes from the original shot order, emphasizes that little Rey was at Luke's Jedi Academy. Luke knows her, which will be his burden as he trains her. And if Luke knows her, there is zero point for her to not be related to them.