This was somewhat expected after recent restrictions on eBay gift cards, but still a big blow. Ebay is now implementing restrictions on eBay Bucks. You won’t earn eBay Bucks on gift card purchases and you won;t be able to use eBay Bucks on gift card purchases. This will almost surely kill gift card reselling.
Here’s the notification that shows up in the eBay Bucks page.
After October 1, 2016, you will not be able to earn eBay Bucks when purchasing eBay Gift Cards, Gift Cards, and Digital Gifts purchases within the Gift Cards & Coupons category.
After January 1, 2017, you will not be able to redeem eBay Bucks for eBay Gift Cards within the Gift Cards & Coupons category.
So you will be able to redeem this quarters eBay Bucks on gift cards at least. Here’s a link to the new terms.