Remember, you asked me to guess...
I am guessing it is Plus-X. If it isn't Kodak and isn't Plus-X I do not know who would or could be making the film in the USA or why Kodak would be making other films for Freestyle that behave enough like Plus-X and Tri-X to be confused as them.
The important point to me is that both of these films seem like good films for what I do. They have a tonal scale and a grain structure I like at a very low price point. Anything else is just conjecture. If you want my conjecture, here it is; maybe Kodak just wants to to keep the film making machines rolling and need a certain volume of sales to do that, even if that means less profit per roll. Maybe it is a way to test demand? Maybe it is supply and demand, they are testing if they lower the price maybe that will stimulate demand? They might be priming the pump.
If they can't sell film at this price point, what is the point of making it? My guess, highlight the word GUESS, is that at a certain point the volume equation has to intersect the cost of keeping the manufacturing equipment running. Then some hard (especially for us) business decisions will have to be made. Hey I have been shooting a lot (for me) of b&w since this stuff has come out, but nothing like the volume of film I used to shoot when I was doing it for a living.
But, don't let me be a gloomy Gus, after all they still make and sell Super-8 movie film. We think we are a niche market?