Almost certainly not. All the offshoots from Mozilla’s tech rely first and foremost on Mozilla’s production of the foundational software, which eats up a significant portion of their roughly $500M/yr operational costs. The heavy development cost of modern browsers is why everything is either Chromium or Gecko-based.

That said, Mozilla will be around as long as Chromium continues to dominate the market. Google literally funds Mozilla because it’s cheaper to prop up a competitor than it is to be sued by the government for monopolistic practices (check out 1998 decision against Microsoft for bundling Internet Explorer with Windows).