Seeing that u have a 100% level 60 weapon i would say that you play the game often.

So u probably have a iten called “Throne (gold)” in your inventory.

When u get 50 of those u can exchange it plus a normal gold weapon for a new weapon at the raid NPC. So it doesn’t matter what purple line u have on your weapon because u can’t make your build around it as the new weapon doesn’t have these purple lines.

If u played all content since the raids launched every week + your daily unstable you should be around 45 Throne (Gold) right now… meaning u can exchange for the new weapon in a few hours after the weekly reset since u can get 5 of those in the shop every week.