No, in my opinion this has zero indication of whether they're looking for a sale. All this means is that they're taking the necessary actions to be able to use the shelf they already had up if they wanted to do an offering of any of the securities registered thereon (which, by the way, includes debt securities, warrants, purchase contracts, units and class A shares (all primary - meaning sold by the company), and secondary class A shares (meaning sold by the selling shareholders - who are not identified in the registration statement and have to be identified in a prospectus supplement for a specific offering)).
When I have done this, it's because my client had a contractual obligation to maintain an effective shelf that registered the secondary shares owned by some of its owners. I'm not saying the club has that obligation (though there may be a registration rights agreement whereby the club has an obligation to do the same for certain of the owners). This is pretty standard practice for filers that lose WKSI status. You have a shelf up for a reason - to be ready and able to do an offering whenever the need arises. When you lose WKSI status and lose the ability to use that shelf, it makes sense to file these amendments to convert the old shelf to a useable non-WKSI shelf rather than having to file a whole new non-automatic shelf.
This is just good corporate practice and not at all indicative of an upcoming offering (which again, could be of any of the type of securities registered on the shelf, not just class A shares owned by the Glazers).
Sorry to burst anyone's bubble - I know the vast majority of us would like them out...