"the NetSuite.com data source is no longer being updated with newly exposed tables and columns, and support for this data source will end in a future release." Any hint about when will this be deprecated?

NetSuite has famously zero support for transitioning, so it’s likely a long time before people are forced out of the first data source, if ever. I think they are saying that if you want future enhancements you need to use the other data source. It’s extremely vague.