Not sure that I would. Seems to me that if you're going to delete the OP of a tread, there's not much point keeping the thread. I assume that was the original reasoning behind this.
No harm in having it tracked though, in case we do decide to change it.
Ant the point is exactly that we have inconsistency in the use of this button.
Here are the cases:
1) topic with 1 post: click "remove" the topic is deleted
2) topic with more than 1 post: click "remove" you get the error "You are not allowed to delete the first post in a topic. If you want to delete this topic, click on the Remove Topic link, or ask a moderator/administrator to do it for you.
Personally I would avoid deleting the entire topic clicking on a "remove" button in a message (unless it's the only message in the topic of course
), so as usual I have a question: why can't we delete the first post of a topic?
Technically is for sure more demanding than delete any other post (you have to set a new id_first_msg...and I think that's all), but it's possible.
So why instead of add another check on each page we don't simply allow to delete the first message and make the use of this button consistent across all the messages?