How does mods remove posts based on sources?

My post got removed despite it being from a reliable source (Ukrayinska Pravda- Media Bias/ Fact check.)

I am not looking to participate in a community where mods remove posts based on their feelings about the source, there needs to be a proof to the mod claim.

Why did my post got removed in this case?

How is the source unreliable, what is the mod proof for that?