From the website, If you purchase a flex ticket you can get Premium seating. That is NOT Business class. Available only on the 787 it is a more comfortable seat. They appear to NOT offer full premium service on those flights, so it makes sense for them to create a class for the most expensive economy passenger to sit there. ( they aren’t going to leave them empty)

If,you look at a flight where full Premium service IS offered, I.e. JFK to TLV, there is no “Flex” ticket. It’s economy flexible”