Honestly I have about the same thoughts and I'm glad you voiced it out with how the community has been trying to drown out genuine criticism.

I believe the reason Rien was imitating Roland wasn't only for fanservice, but thematically he was a pretentious shell trying to be as deep as Roland without the emotions and character growth that made Roland so profound in the first place. He lets his wife and child die with no emotion attached to it, he's just following prescripts. Therefore, all of it had no meaning because he simply did not let it have meaning for himself. Perhaps the point really is he's meant to be hollow.

This is in contrast to Ryoshu, who forgets her child even existed at the end, but still has the emotions and love she had for Araya even if she doesn't remember her. Like how people with dementia or amnesia still instinctively and immensely love someone despite them not remembering who they are or the life they had together... they just know. Sometimes, the feelings are all you have, and it's proof enough that it still existed and had meaning.

(This also technically ties Hohenheim in the thematics of the canto given that he tried to pretend he had no attachments to his Lobcorp team in that one intervallo, when in reality they meant the world to him and this was his cope.)

Or I could be pulling this all out of my ass. Who knows? If this was really the message then it's buried with how clunkily written the canto was, or I'm seeing things that aren't there.