Different problems. One is the regulation of which suppliers can distribute on a platform, deceptive advertising, right-to-repair, and similar consumer protection considerations.
The other problem the article and parent comments are describing relates to the distributor/retailer creating or sourcing generic alternatives to the items sold by their existing suppliers and informing their decisions to do so based on the sales data from their own partners/suppliers.
This latter case seems ok to me, even if it sucks for suppliers, in the sense that we generally get better outcomes for customers. As long as the general regulations for consumer protection are in-place such as preventing confusion between brands and generics.