If you think than being non-judgmental and polite is a fad and commenting on somebody's behavior after the fact is the same as giving uninvited insistent advice to random people, then yes. Otherwise, no.
Today, literally an hour ago, long after I wrote the above comment, I've read a complaint from one of my friends online, that their online community was invaded by preachy vegans (the community has nothing to do with nutritional advice and didn't initiate the discussion on the topic) who proceeded to lecture everybody about how they should give up meat immediately and how they should feel bad if they don't do so. And from what she is saying, it's not the first time it happens in that community. That's exactly what I am talking about.
I think commenting on how this looks like is not the same as what those vegan activists were doing. Not even close.