This was my thought - Nate dying wasn't dramatic/emotional enough on it's own, they needed some sort of "lost love" aspect to it and so quickly rushed a romance. It really did a disservice to both Zari and Nate as characters. I think it would have been a lot more of a gut punch to get more of a reaction from others on the team - Constantine, who made that agreement to get Nate killed to save someone else. Sara, who was so adamant about not losing anyone on the team during this mission. Ray, his bro and the realization that they had sacrificed their lives for each other.
I know Legends is the more funny/wacky show and not so much the "high stakes emotional wreckage" of the other Arrowverse shows, but I think this "death" could have been done better, and then still get the funny "singing James Taylor resurrects people" bit in there too.