Some sites on the network have an additional sidebar box for "Upcoming Events", which is separate from both the "Featured on Meta" and "Host Meta Posts" boxes:
I think this would be a good thing to use for our Language of the Month event. It would free up one of the three featured slots, and would allow for more questions to be shown in the "Hot Meta Questions" bar, promoting more meta engagement.
Unfortunately, I can't find any information about how to set up an "Upcoming Events" box. I'd expect that we'd need to get a CM to set this up for us, similar to our info box, which might require more work from them than is justified for this. According to hyper-neutrino, mods are able to do this, so this should be fairly trivial to set up if we do want it