This is actually described on the wiki itself that the 'angels' are not really angels but manifestations of The Order and its beliefs. Combining Shintoism, Christanity, and Native American religous bases. So it is more safe to say that they are either demons, spirits, or hallucinations made real. This is due to the fact that The Order has very violent teachings and rituals, similar to the idea of demon worship. That's just my two cents, and may be wrong, but it does have a more demonic and punishing feel in the Otherworld then Heaven would feel like.
It's actually more the fact that the town of Silent Hill itself is built on sacred Native American trial grounds. Being native myself, i can explain that the land was meant to be used as a mirror of sorts as it will reflect what is in a person's heart or spirit. So with that being said. A person full of guilt and regret and malice, Obviously will see themselves in a nightmare of all of those things personified and put into symbolism, that at the same time sets them on a pathway that will help to make them understand, forgive, and better themselves (if they survive the "trial") so to speak. While a person pure of heart will only see the land for what it is. This also means that the town is not evil. or haunted at all... It just so happens that the stories in the games we see have to do with people with closets full of skeletons.
One thing to remember about this wiki is that its articles are often limited by a couple erroneous beliefs that literary analysis left in the past long ago:
Error #1: That there is a single, "correct" reading of a text;
Error #2: That the interpretation offered by the creator/author/director/etc. of a work is that single, "correct" interpretation.
So, you will often see flat, incorrect statements saying "X symbolizes Y", as though there were no other possible interpretation, with the "evidence" being, for instance, a link to a forum post by a creator of the game stating their interpretation of the work they've created. However, it will only take you a few minutes to think up an example of a work whose meaning has shifted drastically from that intended by its creator.
Not every reading of a text is valid, not by a long shot. But most of the "theory" and "analysis" you read on the Internet is stuck in the Stone Age due to the errors noted above.