How is redoing the dialogue a simple and easy task? Shakespeare wasn’t even alive until almost 200 years after the events of this game take place. That’s like saying it’s realistic for people in a game that takes place in the 21st century to be speaking like people in the 18th century.
Where are you getting this from? Based on the amount of profanity in the alpha they would have thousands and thousands of words to go through and bleep out, and that is not including the dialogue that has been written for the main story.
According to your own source there has only been five times in the call of duty franchise where profanities have been censored. The others are just censoring of violence, so they did not hardly go through and bleep out every profanity.