Yes, I had to do this back in the summer when I was waiting for a new passport for my eldest DD. Put her old passport number in at check in and then new one arrived about a week later and was able to change it no problem.
I was able to do it just a couple of days prior to sailing. My daughter's new passport arrived just in the nick of time and I was able to delete out her old one and put in the new one with no problem.
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