It's still visible if you toggle 'showdead' in your profile settings. To your question, I don't know exactly why this particular comment had its visibility disa

It's still visible if you toggle 'showdead' in your profile settings. To your question, I don't know exactly why this particular comment had its visibility disabled - it appears to simply be repeating a claim made in the OP, so it's unlikely this was the result of downvoting.