AWS S3 bucket is being accessed from any region even though it is created in us-west-2

Buckets are global so you don't actually need to specify a region in your requests. Still, it's a good idea to provide the right region as it avoids a request going to us-east-1 to find out where your bucket is. Not only it is more efficient but it removes an unnecessary dependency on S3 in us-east-1 so one less thing to go wrong and cause an outage. I haven't tried passing a "wrong" region as you describe but given that specifying region is optional it makes sense to me that AWS would honour the request anyway rather than getting picky. Probably it just means you've added yet more overhead - the request goes to the wrong region, then us-east-1, then the right region.