Thanks for the post! I agree that this would be interesting and potentially valuable. 

Notably we have included some more philosophical questions in the EA Survey in previous years. We included some questions about population ethics, which were requested by an org, in 2019, and some additional measures on some broad normative questions (e.g. "The impact of our actions on the very long-term future is the most important consideration when it comes to doing good"), which were requested by a different org, in 2020. We haven't publicised the results of those requested questions in a post, though we could do so.  In this year's EA Survey, we included an even greater number of broadly philosophical questions of that kind, though, as before, they are in the especially optional 'Extra Credit' section of the survey.

I agree that surveying EA's views about more (and more explicitly philosophical) questions would still be valuable. We haven't included more questions along these lines due to space constraints. Rethink Priorities would potentially be interested in running such a survey- we have a number of philosophers and social scientists on staff- though we think the risk of 'survey fatigue' means we should be careful before launching more surveys of the community. A survey like this could also potentially be combined with other projects that seem potentially valuable to the community (e.g. getting a more fine-grained sense of the beliefs and cause prioritizations of highly informed EAs).