The idea that a developing Queen is able to spawn guards doesn't contradict what we've seen in any of the films so far, if anything, as I mentioned earlier, it adds a second angle to egg-morphing. The morphed hosts could very well be the result of the regurgitation embryo implantation, spawning guards rather than a Queen herself.
Although this puts the "super-facehugger" in an awkward position as well, since egg-morphing was supposedly meant to be the method by which they were created, although we've seen evidence that a Queen can lay an egg to produce a super-facehugger in order to spawn a second colony of aliens & further populate the species, so that fills in the gap fairly well.