There were actually 2 Beastmen leaders that were kinda opposed to attacking the Tower and using humans. But they were force to by these 2 main Beastmen. The cow woman and the bird guy, I think. So maybe they will be "forgiven" and then put in charge?
Well it's entirely up to whether Light actually needs them or not. A foreign power has no obligation to recognize different factions within a country, and at the end of the day, you chose democracy which means shared responsibility even for things you opposed.
I feel they should come down somewhere between the dwarves & night elves vs the elves. Dwarves willingly allied themselves with Light, the Night elves didn't but he got to influence who became the new leaders, plus they have a predictable and quantifiable self-interest. The Elves openly opposed him, so they're completely untrustworthy and screwed.
The remaining beastmen leaders night have opposed it but they respected their own process and ties more than disagreement. Ironically the fact that they are unlikely to betray each other works against them here. That's on some level inherently not trustworthy to human causes for Light's purpose. He probably will want the beastmen country to remain intact like all the others, so they get to live but I wouldn't be surprised if he also basically made slaves of them.