Hi TexasRSA,
Welcome to the Mattress Forum! 
There are many brands that run on margins that are the same, or even higher, than Tempurpedic, many of them in a similar model of tightly “price controlled” strategy. These large margins are one of the very reasons that salespeople (RSAs) can be so heavily commissioned and spiffed to sell such products, and why many RSAs prefer to “recommend” these products to their customers.
While Tempurpedic mattresses generally use good quality materials, they are in much higher (and mostly unjustifiable) budget ranges and for most people they certainly wouldn’t be in the best “value” range compared to many other smaller manufacturers that use similar (or in some cases better) quality materials that are in much lower budget ranges. For consumers, there is more about Tempurpedic in general in posts #1 and #2 here.
But higher margins are not found just in higher-priced items. Many stores make very large profits (sometimes 3x cost) on lower-quality items that are made to “look” like they are a high-quality item, but offered at a much lower price. Some of these can return a margin even higher than brands like Tempurpedic.
This of course makes it that much more important that consumers educate themselves with items like the mattress shopping tutorial here, and also find out information listed here so that they can compare the quality of the materials and components to the durability guidelines here to make sure that there are no lower quality materials or weak links in a mattress that would be a cause for concern relative to the durability and useful life of a mattress before making any purchase, and also use that information to compare different mattress models/brands to each other.
Unless they are part of the board meetings of Tempur Sealy (and then they wouldn’t talk ), anything would be speculation. What I’ve read from various analysts speculates that TPX could certainly recapture much of their volume over time through expansions to other retailers (and the growth of those retailers themselves, such as Mattress1One); a rekindling of their agreement with Mattress Firm, or an acquisition of a company like Steinhoff/Mattress Firm. I haven’t run across anything that hints at TPX changing their channels for selling to online, but that would be a very large change in how they do business if they decide to go online and would potentially lead to fewer brick and mortar stores offering their products as well. Of course, just because I haven’t heard of something has no relevance, as I am not part of any “inner-circle” of information regarding this besides the analyst reports that are available publically.
While talking about this is a little off the path of the normal conversations here on the forum, it certainly is interesting to speculate and guess what is going on behind the scenes of these large companies.
Phoenix