Three thoughts. First, the overwhelming majority of users who we stick up for with comments like this (including the GP) aren't affiliated with YC in any way, so I don't see what problem that would solve.
It would insult readers' knowledge and intelligence to put nitpicky disclaimers on everything, especially when the affiliations are all public. Presumably you knew these things without special access; why assume less of others?
HN is a spirit-of-the-law, not letter-of-the-law place. The principle at issue is that fellow users deserve to be read charitably. I don't see how that needs any disclaiming.
Note 2: This kind of comment from a moderator feels a bit out of place, given this. At least without a disclaimer explaining the relationship between the topic and the moderator's employer.