There can be lots of reasons that a company mistreats their customers. I would be very hesitant to say that every instance of mistreatment of customers is an indication of monopoly status... and while they are (were?) the most popular ...
https://www.traqline.com/newsroom/blog/us-fitness-equipment-...
> As of September 2023, the most popular Fitness Equipment manufacturer continued to be Peloton, in both unit (11%) and dollar (25%) share.
> However, as seen with outlet share, Peloton saw decreases in brand share. In dollars sold, Peloton saw the largest decrease in share across all Fitness Equipment brands, with a loss of 4 points YOY; in dollar share, Peloton lost 1 point.
That does not look like a monopoly.
Rather this looks more like desperation from a company on its way down trying to milk any revenue out of its customer base.
Weight gain in association with other changes is still a signal for pregnancy, just as mistreatment of customers in association with other characteristics of monopolization is a signal of monopoly status.
If one wants to claim that some company of a monopoly - they should back it up with more than one signal... such as a dominant position in the market, no substitutes for the products, or lack of concern about other companies entering the market (such as NordicTrack).