Yes, but with more criteria than "cheap knockoff". There's a lot of companies these days that satisfy the niche of "printers that print well and quickly out of the box without tinkering". Furthermore, many of them are priced below Prusa's offerings.
"Cheap knockoff" implies a significant degradation in quality, but the reality is that they are of equal quality, and lower price - the fact that Prusa is open source and has a good reputation as a brand can make up ground, but in the end many consumers mainly care about meeting a certain standard of performance, and then sorting by ascending price.
Prusa went from niche to fairly mainstream by being the printer that "just works". Mainstream is way more money than the enthusiast, hobby segment of the 3d printing market. So they would feel the burn from having those sales lost.