If you think this "purge" is about nose art, I'm pretty sure you're wilfully missing the point.
This. Although "wilfully" is only valid if some of the people posting here are aware (or want to be aware) of what is happening in the USA right now. I suspect "wilfully" is actually a back-handed compliment to some of the posters on this thread.
I strongly suspect the US military are taking a stance against things like the QAnon b/s and all the paraphernalia associated with it. Obviously they cannot be specific, nor would they want to be. The UK military has taken a similar stance over proscribed organisations and displays relating to them in the past, but in 2020 its getting harder to do this and the authorities have to be necessarily more nuanced.
I think all this nose art discussion is completely irrelevant to the original post, as is all the clatter about "changing history". This is about keeping a cult the FBI have branded domestic terrorism out of public service. If you want to know how deeply this has ingrained itself in US society a few minutes work on Google/WiKi should waken up the audience.