1) Things that are actually Netflix's shows, like House of Cards
2) Things that Netflix bought exclusive distribution rights for in the US and markets as "Original" just like House of Cards, but actually had nothing to do with.
So it's less that Netflix sold the rights to local TVs and more that they never had those rights to begin with.
"Netflix Original" clearly doesn't mean much. I think it'd be wiser for Netflix to reserve it for shows they actually own, so they can never disappear from Netflix.
I thought I still saw it listed recently. Maybe it's only gone from your region and not mine, in which case I recommend a VPN.
3) Joint productions like Lilyhammer where Netflix partnered with a foreign broadcaster to produce.
So something like Lilyhammer that was a joint Netflix/NRK production means it's a Netflix Original in the US and aired on NRK1 in Norway, but it's actually produced by both companies.