Is the purchase pilot already closed? I don't have the option to opt in.

Did you sign up for the Console Purchase Pilot through the Xbox Insider Hub like the article that you linked says to?

"If you’re interested in potentially buying an Xbox Series X or Xbox Series S, you’ll need to hop into the Xbox Insider Hub and sign up for the Console Purchase Pilot through there. Good news if you signed up last time and weren’t selected: Microsoft says that you’ve already opted into this round and won’t need to do anything for the chance to be selected again."

Hello PsYcO CrAcKeR,

In order to be eligible for the Simply Rewarding offer, you must make your purchases after opting-in to the offer. If your purchases were made before opting in to the offer, they would not be eligible. However, it is possible that if you purchased and immediately
opted in afterward that delays in data could cause your purchase to be eligible. However, since it takes us up to 96 hours to purchase information, we have not yet received your purchase information. If your purchase was made sufficiently close to opting in,
you should see progress for the offer in the next few days.

I don't think there is an option to opt out, but you'll want to post in the support section of this forum to see if support can opt you out.

Hello IM NOT COW MOOO,

We see that you have already clicked the opt in button on the MyMission page for this offer, and have opted yourself in, as shown by the buttons changing to direct you to the store on the mission page. You're good to go! We see that we have already processed
your consumable purchase on March 1st toward this offer.

Hello CrimsonReLLiK,

In order to start progressing the Simply Rewarding offer, you must first opt in, as stated in the FAQ for the offer. Since your purchase was made on the 2nd, and you opted into the offer on the 4th, that purchase was not eligible. However, I can confirm
that this is a literal $60 before tax, as stated in the FAQ.

This offer is unique in that it requires an opt-in before progressing the offer. Most other offers do not, and for example, you have been awarded a Games on Demand punch for your purchase already.

Also, this offer will allow double dipping, so if you purchase another Games on Demand eligible title, since you have now opted in to the offer, it will both award progress for Simply Rewarding as well as a Games on Demand punch.