Just making this as a separate placeholder for merging any questions about this to.
If you purchase Valor Pass at any time during Path of Valor, Premium Rewards for Milestones you’ve already earned will unlock.
You don’t need to buy Valor Pass in advance of completing Challenges or unlocking Milestones in order to get the Premium Rewards.
You just need to buy Valor Pass before Path of Valor ends — so you can wait to purchase it until deciding if it’s worth it to you, if you’d like.
For discussion of Path of Valor, please see: