Rustication purely comes down to briar quality. If the briar has fantastic grain with no flaws or pits, the pipe stays a smooth. If the briar has poor grain, lots of pits etc. the pipe will be sandblasted or rusticated.
Smooth pipes with stellar grain command more money. So to answer your question, no. If a pipe maker has great briar, and it happens he's making an army mount, keeping it smooth would be the correct thing to do.
Sometimes a pipe is just a pipe.
With all that being said, I get where you're coming from. Over half my collection are rusticated pipes. I think rusticated billiards with straight stems are just plain masculine.
Luckily, you can buy any pipe for any reason ya want! So if you think army mounts should be rusticated by principal, you can buy one!