Humanity has expressed celebration and reverence of different seasons and natural phenomena in various cultures, sometimes with traditions bearing varying degrees of resemblance to each other. Eid al-Adha, one of Islam's two main holidays, involves animal sacrifice to Allah--a practice not unlike other sacrificial rituals found in various cultures throughout history.
Does this mean Eid al-Adha is a co-opting of pagan rituals? Of course not: there is no evidence to conclusively suggest such a connection. What it definitely demonstrates, however, is that humans are more similar than we think both throughout history and across different cultures and countries. In my opinion, focusing on how to best coexist and respect each other's rights to have diverse cultures, traditions, and identities is much more important and useful than endlessly debating whether or not one practice "appropriated" another--except in cases where that actually affects anyone's lives or human rights, which is a very rare scenario nowadays.