It rewards players who have invested in characters that might not be meta, while encouraging everyone else to farm them as there is now a reason.
Also, this is completely different than the Thrawn situation. Phoenix were only farmable for around a week before that event. FO have been around pretty much since the start of the game. Yes two of them are behind hard nodes, but FO plays a significant role in the current trilogy, so it would only make sense that they're needed for something.