|It's good... but also not|
I can already hear the outrage by my two readers, "what do you mean under ANY circumstance?! Have you no respect for the dead? For their families?!" Sure. I sympathize for those who lost someone they cared about and respect their love for that person. I would happily and passionately argue the life and death of their loved one should be kept private and is not in the public's interest unless their cause of death is a public health concern. Otherwise, that actor's life/death is of no interest to me except in the manner in which they wanted it in the public eye.
But the character they played, in almost all instances, does not belong to the actor, even if they think they do. The actor is a professional. As a professional, they are paid to do a job. That job is to make us believe the character they are playing is not the actor. If the actor passes away and the character remains so important a studio/producer wishes to bring the character back, inspired by the work and look of an actor who passed, I see that as the ULTIMATE respect and honor. The actor did such an amazing job, and the character was so important, that not even the death of the artist who brought the character to life can silence it forever.
Apple didn't stop making iPods because Steve Jobs died. They didn't only make the final generation of the last technology he made because it would be disrespectful to keep making more. They kept making more and will keep making more, because doing anything else would be to deny the passion of the art Steve Jobs saw in that which he brought to life.
A facsimile of art will never be the original, and yet musicians sample the work of those who came before; perform and sell covers originally written by their heroes; and dress, behave, and act on stage in ways they saw from those who came before them.
All art has methods of reproducing what came before. It isn't going to stop in film or television because some people have a negative reaction to a character being played by someone else with an avatar carefully filled in. The original actor is gone. That piece of 1s and 0s acting like a version of a real person is just a costume, not too different from the one the original actor wore when they created the character.
Would you demand no one else ever use words or terms created by a famous writer once they passed on because they were so unique to that writer it would be impossible to not associate with them? If so, abandon the many words Shakespeare coined/invented that became part of our everyday cultural expression. The silence of the world would be deafening... a word some think was one of Shakespeare's but wasn't. However, had I not told you that, you would have believed it because you have no clue how many words or terms you use every day were not originally part of the English language before some artist gave them to the world.
Bring forth your grand CGI machine and unleash the soul of avatars performed by living actors. Let's save our outrage for when they stop using human actors at all. Though, let me close with this caveat: it should be done whenever it can be done provided it doesn't take the audience out of the movie due to the technology not living up to the needs of the human eye, like it does in "Rogue One: A Star Wars Story." While the CGI is impressive, I can't stop noticing Tarkin looks like a highly rendered video game character. I've watched the movie more than half-dozen times and no matter how much I squint or how many ounces of vodka I drink, it doesn't work for me in any scene.
In conclusion, please recreate characters with CGI after actors, who originally played them, pass away, on to the great Force cloud in the sky... but maybe hold off until 2025. Or whenever you've figured out how to not make it look creepy.