That's how it is. You gotta finish the missions in order to advance the levels of the weapons that you can gain. By the time you finish in the first playthrough, the legends will come as level 35. By the time you've finished second playthrough ,the legends may be at 50. But in third playthrough,you can have a 100% guarantee of a level 50 legendary weapon.
The level of items from the slots are based on your game progression. You need to finish the game on true vault hunter difficulty to get level 50 items from the slots.
Correct, I'm no on my second play thru at level 40 and still do not see any Level 50 ORANGE items.
I will continue to test this out as I get closer to finishing my second play thru to see how these items progress in level, I have gotten some LEVEL 38 items however, but many are not as good as the purple/lavender items from the gold chest I currently have.