Need to get the nomenclature straight.
The Unocal 76 competition held in the fall at Rockingham is still on as far as I know. After this year, since 76 is not going to be the fuel of NASCAR, that might change, but no word on that yet. That is a straight head to head contest to bring the car to the pits, change four tires and refuel, then leave the pits. Best time, less penalties for loose/missing lugs, wins. The Dewalt is the two time defending champion of that competition and currently holds the record for best time.
The Macdonald/Powerade competition is a weekly comparison. It awards the team which spends the least amount of time on pit road at each race. A cumulative winner will also be declared at season's end. This is the first year for this competition sponsored by MacDonalds/Powerade, though the competition has existed in the past sponsored by Ingersoll Rand.
No team is not allowed to compete; every team on the circuit is eligible The problem with a few teams that are sponsored by competitors such as Pepsi or Gatorade are not competing at their sponsors insistence. It is not that the competition will not permit their entry. Conflicts in sponsorship are nothing new and the requirement to run a decal to be eligible for any contingency award such as this is common as dirt. every team runs Unocal because they have to, so there can be no conflict there. Nor is a conflict inherent in certain sponsorships, you will notice that Rusty runs in the Bud Shootout despite his Miller sponsorship. The culprit in this case if one must be named is Gatorade/Pepsi. It is nothing new and much ado about nothing.