I use AWS daily. It takes a few days to figure out those warnings are mostly there because some customer found out the hard way what they mean. You ignore them at your own peril.

And seriously:

> This action creates a copy of the object with updated settings and a new last-modified date. You can change the storage class without making a new copy of the object using a lifecycle rule.

I hate the AWS Console UI for a bunch of reasons, but short of making you type that sentence before you proceed, I'm not sure what AWS can do here.