This seems like a pretty large nerf to how weekly mission rewards are provided to us: https://i.imgur.com/EdLRQPr.png
Previously, you could buy the event pass in the final week and you'd still be able to do all 4 Weekly Wins missions in order from 1 to 4. Now it seems that if you buy the pass in week 4, you've permanently lost the 750 tokens from weeks 1-3.