"Under the new policy, my comment could be considered gratuitously negative, no?"
No, your comment would be fine. The idea is, if you're going to be negative, at least be thoughtful about how you want to say it. Looking at it a different way, if you're negative, do you take the pleasure from being honest or from being dramatic? If you take pleasure from being honest, there's nothing stopping you from being both honest and welcoming. If you want to be dramatic, do it as a joke, but don't do it to boost your ego, and go after the idea rather than the person. There are ways to have your cake and eat it.
No, your comment would be fine. The idea is, if you're going to be negative, at least be thoughtful about how you want to say it. Looking at it a different way, if you're negative, do you take the pleasure from being honest or from being dramatic? If you take pleasure from being honest, there's nothing stopping you from being both honest and welcoming. If you want to be dramatic, do it as a joke, but don't do it to boost your ego, and go after the idea rather than the person. There are ways to have your cake and eat it.