Interesting article, though while there are some differences between how death as a concept is depicted in the OG and AC, I don't think they are as different as the article makes them out to be.
Firstly, IIRC didn't the "living legacy" lines originate in Crisis Core not the original version of AC? Albeit the scene gets added to the Complete version, but I think being accurate on the source of one's criticisms is important.
Secondly, while it is true that Aerith doesn't speak to the party after her death in the OG, I don't think it's accurate to say she doesn't have a significant/interactive presence after her death in the OG what with the Church Ghost, the reaching hand, and the literal ending shot of her face in the climax. Now maybe for some the difference between that OG stuff and what AC/C is significant, but for me the difference is negligible.
Additionally, I think the ambiguity of Cloud's "conversations" with Zack and Aerith in AC/C shouldn't be discounted, it's deliberately allows for some of them to be interpreted as "just in Cloud's head".
Also Rufus isn't seen "clearly dying" in the OG, yes one would presume he was dead without AC/C, but if one is being pedantic about Aerith, one should be so with Rufus as well (which the OG gave a "no body shown" opportunity for AC/C to take).
And finally I don't think using Sephiroth's revival in AC/C is a good example of "death losing its meaning" when Sephiroth dying and later being revealed to not actually be dead is a major plot point of the OG as well.
Anyways, while I do agree that AC/C is approaching the theme of death differently than the OG did in some respects, I don't think they are irreconcilable with each other like the author of article purports. Especially when the theme of AC/C is dealing with guilt and having to live with grief afterwards, while the OG is about loss in the present, since different aspects of dealing with death are being depicted between the two works, I think some difference in approach/depiction should be expected.