I think the question regarding the effectiveness of the Leia scenes won’t really be answered for another 10-15 years, where a whole new generation who weren’t even around when Carrie was alive can experience these movies without the knowledge of Carrie’s passing during the making of this new trilogy. We’re lifelong fans who consume whatever Star Wars news we come across. How will it be for a first time viewer, or a brand new fan?
Personally I just think the main reason for the critique is it’s an easy thing to latch on to, and you can extrapolate all sorts of bad storytelling philosophies that come from the decision, whether the decision itself has anything to do with the bad storytelling of the film. I think the truth of the matter is more nuanced. Some scenes work, some don’t. I think there’s a world where the film as a whole is better, and people give the Leia moments a pass. It’s a little telling that no one complained about the idea before they saw the film.
At the end of the day, I always come back to this - her role in the film is extremely minimal, and has nearly no effect on the plot or any of the film’s worst decisions.