Considering that observations of evidence of organisms are valid Research Grade observations, and not discouraged in any way, what is it that makes the graphs implicitly referring strictly to living organisms? All they do is describe what the set of observations indicate, and there’s nothing stopping anyone from adding evidence of an organism as an observation. If a researcher wants to use the data making up the graphs, he or she should have a look through the observations to make sure they’re all helpful for the purposes of the research (as I assume should be done for any data set for research).
What if, hypothetically, you had a species where males and females are active and visible at different times of the year, with males appearing in one month and females appearing the next month. However, a male dies and you find it on the ground a month later. That woud technically “mess up” the graphs, but I don’t think it’s reasonable to prevent people from marking the sex of the organism. However, it would be easy to find and filter out.
Or if a Type of Evidence annotation is added, then a researcher could filter out any observations that don’t have the value “Photo of a living organism”.