I would not suggest you ever 'buy ahead' with SK deals. So few of the deals respawn, and the SK credit is the vast majority of the deal. So if it does not repopulate, you end up paying $1.50 of the $2 price.
Chances are good that Welch's will come back for you as well, but I personally would wait for the offer to come back before purchase.
@Dean @mickootay @Rickibotta I ran into inventory issues as well. Try scanning other flavors to see if the kicks are awarded. I did that with the Passion Fruit “Lemonade”, and it worked, so I was able to purchase that and get the 500 kicks.
At the time, my Concord Grape and Mango offers were still in pending status, so I couldn’t do similar tests. Those have since been awarded, though those flavors are long gone. I’m hoping there’s another grape-ish variety that will satisfy the Concord option.