The way I see limited jobs is a way to be more faithful to what makes the jobs unique by making them side content, without the usual balancing etc that comes with normal jobs, that otherwise might not get added or if they were added, would suffer more for being molded into a formula. For that reason I don't mind the way blue mage is handled and wouldn't mind seeing beastmaster implemented that way.

In fact, if they do add a second limited job they did name drop beastmaster as a potential limited job. I believe during the fanfest where blue mage was announced but would need to double check where. So I wouldn't be surprised at all if in say 5.4 or so we got beastmaster.