Snark definition:

“an attitude or expression of mocking irreverence and sarcasm”

Source:

https://www.merriam-webster.com/dictionary/snark

Indignant definition:

“feeling or showing anger because of something unjust or unworthy”

Source:

https://www.merriam-webster.com/dictionary/indignant

So just based on these definitions that comment seems neither snarky nor indignant? There’s no anger because he’s a moderator calmly stating one of the rules of the site. And there don’t seem to be anything mocking, irreverent or sarcastic about him calmly stating the site guidelines?