I believe this has more to do with different ingredients in the "professional" category. Modern professional bakeries(whether industrial sized or not) often have access to a wide variety of additives, some of which are not even required to be listed on the "ingredients" list specifically. This varies widely by country; common euphimistic examples of such ingredients in a very general sense include words like "spices", "emulsifiers", "softeners", "stabilizers", "anti-caking agents", or "preservatives".
I would suspect a hydrophilic substance first. Commonly used "softeners" are various plant based gums and fiber. Think guar gum, xanthan gum, inulin, cellulose, or psyllium husk. A cookie which I know to be very high in one or more of these softeners is known across the U.S.A. as "Chips A'hoy Chewy". These cookies tend to stay softer in almost any condition, from frozen to relatively dried out/stale, than home made cookies.
All of these potential ingredients are available for the home chef today(including many I have not mentioned), but would not be typically found in your kitchen or at your local grocer. You would want to look at a shop or online vendor specializing in "molecular gastronomy".
One of the things I do with cookies in general(which would not work very well with anything frozen, but I feel the need to mention anyway) is to place a slice of bread into an airtight storage container with fresh cookies after the cookies have cooled to room temperature. This will keep almost any kind of cookie softer than other storage methods, while the slice of bread will seem to have dried out significantly by comparison. This precludes the use of additives entirely. I suspect this probably also carries a higher spoilage risk, due to the addition of humidity, although I've not had any issues with cookies spoiling this way before they are eaten(usually within about 5 days). Refrigeration would help tremendously if there was a desire to keep them far longer, although I would not recommend freezing.
All that said, I have little experience with macaroons, specifically, so your experience may vary.