Whether there is more in game than the barnacles at this time, there is a chance that there is, but at the same time there is a chance that there isn't. The developers cannot give too many hints as to what there is or isn't. The way I look at it, the mystery behind the UAs and the Barnacles is what makes the search and investigation exciting, not knowing exactly what they are or what they do.
In a way, this "mystery" is what separates the true explorers from the ones that are not that serious about exploring. If FD reveals that something is indeed there (as in the barnacles, it was said they were in game and even how to possibly find them) everyone will scour the game to find them, knowing there is something to be found. The barnacles were found within a month of Horizons release, simply because we knew where to look and knew they were somewhere.
If, on the other hand, it's kept a mystery, the true explorers among us will keep looking, because that's what we do, find that which no one has found before. It adds to the excitement of exploration, looking for the unknown.
I think of this like the explorers of old. They would set to sea and often spend days, weeks, or even months before they found anything worthwhile. But, I can only imagine how they must have felt when they saw a new land, a new island, a new place that was previously unknown and uncharted. I am sure there were a lot of explorers back then that set to sea, and I am sure there were many that gave up as time went by. Only those who persevered were rewarded with the find and experience of their lifetime.
In a way, I consider Elite Dangerous exploration to be similar. We are the Cristobal Colon, the Christopher Columbus of our Galaxy. We are the intrepid explorers that put up with tedious, long days of finding the same similar things over an over. We are the ones that leave our homes to return days, weeks, or even months later.
And those of us who persevere, will be the ones to see, discover, and experience the things firsthand before anyone else does.
Even if there is no more in game than the barnacles right now, since we don't know, when FD eventually adds more and we find it, we won't know any better. The only thing we'll know is that all our time looking "paid off".
At least in this instance, ignorance is indeed bliss. Knowing where something is takes away from the excitement of finding it.
Currently, I am in Skaudai sector scouring the nebula here. Once I get tired of scanning systems in this nebula, I plan to more on to another nebula, then another. I have been exploring the nebulas before I even knew about the barnacles, so now I want to see if I can find any on any other nebula.
All I can say to my fellow explorers is, set out into the black, and let's solve this big mystery together!