Wow, talk about a roaming thread. . . insults, apologies, fishing!
Back to the topic. It has been summed up fairly well, but thought I would give my take.
As discussed earlier, if you want feedback on why some of your fruits don't shine in your mead, then noting all fruits may be appropriate. (I do like the concept of stating all of the fruits but then also adding that the primary fruits are x and y). If you are wanting to do well in the competition, mention only the ones that are detectable.
A correlation can be made to deciding what style to enter in beer brewing. You may brew what you were planning to be a Robust Porter, but for whatever reason (lower mash efficiency, old ingredients, attenuates too much, etc.) it just doesn't have the proper malt and hop kick and ends up more of a Brown Porter. Tastes like a Brown Porter, looks like a Brown Porter, smells like a Brown Porter, feels like a Brown Porter. I say enter as a Brown Porter. You can enter as a Robust and you will likely get comments back that the alcohol, hops, body, etc. are too low for the style and to enter as a Brown Porter next time.
In any event, it's not an ethics thing for any of these cases. Just because you add it to the grist (or must) doesn't mean it's going to shine in the final product.