I've recently had two of my videos, both of which are survival horror let's plays, set to the "Not suitable for all advertisers" yellow dollar icon as well. I contacted Freedom! Support but there wasn't much they could do except escalate it to higher up. Needless to say, it puzzled me as well because those two videos had nothing in it whatsoever that would even remotely violate YouTube's acceptable content guidelines, at least not that I could think of anyway.
I kept talking about this on videos by other channels that are also being affected and have made videos expressing their displeasure over what many and I see as YouTube going to extremes to keep advertisers happy, at the expense of content creators who spend upwards of 6 hours or more working on videos (my videos take that long from start to finish). From what I've seen, this problem is quite widespread and many Youtubers that I know of are affected by it, so you are definitely not alone.
I've now had one of my videos restored to the normal green dollar icon, I don't know if YouTube has realised what a big mistake they're making and are now taking steps to restore confidence to content creators and repair the damage, but hopefully this is the beginning of a brighter future for everyone, not just for the advertisers but us content creators as well. YouTube needs to see us as their friend, not their enemy. I think if they want to find a solution that works, they need to work with us, not against us.