You are allowed to wear one, you are encouraged to wear one, directly from primary source

https://hirbawiusa.com/blogs/hirbawi-stories/but-im-not-palestinian

It is okay to be Palestiweeb. Regardless, it also makes a beautiful wall decoration, and these days made in Palestine scarves are hard to get by. So I understand people want to cherish and display their keffiyeh without risking damaging them.