It was dead for about 10 minutes after I posted it, I think it tripped up some spam/troll filter for new accounts. It's fine now though, but I can't edit the original comment and remove the last line.

Yes, new accounts tend to have their comments appear as dead until they are vouched for. For constructive posts this usually happens quickly.

It can be brought back to life if people vouch for it, so I assume that’s what happened.