Well, the most likely answer is that even though the human genome is outstandingly well-annotated, there are still some corner cases that are missed out, plus the incredible heterogeneity of biology and absence of 100% precision on these things. If you plot a histogram on the log10-length of gene types you'll see that it is very few genes that have that short length. After all, why is it bad to have an RNA with only 200bp? It is still "longer" than typical short RNAs. Unless you're working with exactly these genes that are concerned here I would just ignore this.