Twinkies, Ding Dongs, Zingers, etc won't all vanish.
When a company has a controlled closure like this they:
1. Sell off the factories. They can sell to private investors, the competition, the city/state, etc. It is rare for places like bakeries to keep empty unsold factories. Too many other businesses will want them b/c they are perfect for their baking needs.
2. Sell off the equipment. They'll most likely sell to other bakeries BECAUSE
3. They sell off the patent/trademarks on their products that kept other bakeries from making Twinkies, TO INCLUDE patents/trademarks on the special equipment used to make something just so.
4. They sell off the recipes
In six months or less I bet new "Twinkies" are being made by Little Debbie.
I mean, patents/trademarks are a complicated business. When these snack cakes were "invented" they rushed to get them protected so nobody else could make them. Other bakeries could do things kinda close, but none were allowed to vendor anything that too closely resembled a Twinkie. With the company going under, they are most likely going to sell it off or let the patent/trademark expire, and other bakeries will rush at the chance. Hell, they may even make a BETTER Twinkie! You know, one that doesn't have the consistency of a dish sponge and leave that plasticy residue in your mouth?
For an example of an expiring trademark/patent error on a large scale:
The McMuffin. McDonald's Corporation failed to file the renewal in time, which resulted in Burger King's obnoxious commercials of that disgusting King mascot breaking into HQ and stealing the recipe for a freaking egg, sausage, and english muffin sandwhich. B/c McDonald's failed to secure their renewal in time, the "McMuffin" is now available in exact replication at Burger King.
So rest easy. All those snack cakes you never ate but know you loved won't vanish. They'll just be reborn. In the meantime, Little Debbie has some good cakes, too. B/c really, most of them all tasted the same. Some sort of over-processed condensed sugar in cake form topped with a plastic-like frosting surrounding a gel cream that left a gross residue in your mouth.
(Personally, I will miss Zingers. I haven't eaten any in well over 5 years, but until they are brought back elsewhere, it's sad the option won't even be there!)
And if all else fails, look up recipes online for homemade confectionaries resembling your favorites. Some savvy bakers found recipes that mimic them PERFECTLY that you can make at home with ingredients you can pronounce!