At least when consuming OData 2, Salesforce does not support Collection(Int16|Int32|String). Since we expose our system metadata, including pg metadata, in the OData metadata, this means that Salesforce won't consume. If the pg metadata is disabled and there are not primitive array columns in the rest of the metadata, then Salesforce can consume.
Since this is working around a Salesforce issue, we shouldn't introduce too intrusive of a mechanism for this. And in general we may need to use extension metadata to allow users to exclude objects in a more granular way from being exposed in OData metadata.