I really like the idea of the (probable) future introduction of "General reference" flag. Especially the last note is gold:
Allow your Q&A community to fill itself with enough “General Reference” type questions and you’ll soon find no experts there at all.
I think the issue needs some clarifications before it can be used in our FAQ. The flowchart in the blog post is useful and good tool to quickly decide if a question is too simple or not. However, I don't think a flowchart is really new-user-friendly and would be more effective with some examples or at least different wording to make it seem like it is targeted at the (Graphic) Design SE rather than at any Stack Exchange site.
Side note:
Furthermore the issue is not only having "too simple" questions but also "too simple" answers. I have seen many quite fundamental and 101–style questions been asked in Photography SE, but the quality of the answers have made the whole Q & A more interesting.
For example: What does f-stop mean?—see the interstellar difference between the most–voted and least–voted answer. If the possible "General reference" questions are populated with LMGTFY-answers and quick link storms, the answers make the question too simple. If a wandering expert visits the site and sees simple questions but expert answers, heshe would find the community interesting.
Do we have enough expertise to answer these general reference questions in an interesting manner? Or should we wait the community to grow?
Some questions still are too simple. And this meta-question is about them.
How we should indicate that "How can I add drop shadow to my logo" is too simple but still courage people to ask a wide range of questions? Try not to ask anything that could be in your product's manual or Ask anything that wouldn't fit an introductory course of graphic design?
What about "What exactly are ligatures?" Most probably any designer has seen the term and has at least shallow knowledge of what it means. It is the same kind of a question like "What does f-stop mean?" at Photo.SE—it can be answered interestingly if the answerer sees it as a wider question than just a request for googling the term. The last point in the flowchart would either close this question as "General reference" or be answered with a high-rep answer.
Should we also discourage too simple answers? And how should we address that?
Sane answer is "let the community decide", but the FAQ is for new users who necessarily haven't got the grasp of the ethos in the community. And it would lead to a better user experience if the new user understands that hishers question might be too simple for this community than it would be to see the question to just float around without any answers or to see the question be closed completely.