So the pool is completely melted now, but I thought I'd share what happened about a month ago.
We had repeated freezing/melting, I had a good amount of water on top of the cover, and no air pillow (it blew off at start of winter).
What happened was the ice under the cover ended up being shaped like a bowl, and the ice around the edge pushed up and got under the plastic on the sides of the pool causing them to bend back and push away from each other. I assume this is because lack of air pillow and water on cover?
Anyway, it's all melted now, no damage to liner. The sides of the pool seem more loose (I don't remember how loose they were before) but I can wiggle a side post and watch the posts next to it wiggle in a wave. It could've been like this before, it seems stable enough. Any thoughts? Thanks!