That's what I'm thinking. Only thing is I don't see Luke taking his fathers helmet only. All speculation mind you but taking his dead fathers helmet alone seems a bit morbid...where as I can see him wanting to give his father a proper resting place....meaning all of the remains.
Then, if you consider Kylo Ben taking the helmet from his dead grandfather's grave...you kind of get a deeper sense of how messed up Kylo Ben is. I dunno....I think there's got to be something more to the fact that Kylo has Vader's helmet. How did he get it? Were the remains hidden in some temple? Did Kylo go to Endor to find the remains? Were the remains even left on Endor?
It just seems to me that Vader's remains would end up in some protected place...a jedi temple of sorts seems to make sense, and Luke appears to have had one.
Again, just thinking out loud here...and sure, I guess I'm wanting to believe there's more to it.
David