The question was asked, " Could the message embedded in the final celebration be that: Jealousy and Honor can have tragic consequences and that in the end, good always overcome evil?"
And " What do u think the secret message is, that lies embedded in the final celebration?"
Great questions. The short answer to the first is, sadly, not really, and to the second, no secret at all—it is a comedy.
To expand on those a bit, the final term is key. This is a comedy, which means not that it should be dismissed, but that it ends well and happily. There is laughter along the way, but also, the situation is resolved well. Comedy gives us an image of the world we wish were the case. Tragedy gives us an image of the world we fear might be true. Because this is a comedy, we can sigh and say, "Wouldn't it be nice if we could trick Beatrice and Benedict together? Wouldn't it be nice if the slander Hero suffered could be washed away? And wouldn't it be nice if good always overcomes evil?" It would be nice, but that's not the message. Because it isn't the message—because defeating evil requires pain and blood and suffering—Shakespeare lets his characters put off dealing with John for another time. Today, they celebrate, and that, if anything, is the secret message: when you get a chance for love and happiness, seize it. Focus on it.