The problem within the Furby community is that any toy with bird like features tends to be labelled a Furby fake. This is due to it being fun and exciting when a new fake is found.
I expect that Tomy have created many bird like toys, which have been incorrectly branded as fakes.
Some of the "fakes" do contain parts from Furbys, this still doesn't necessarily make them a "fake".... If that were the case, Furbys themselves would be considered fakes of Takara's Rock'N Flowers, as they share some of the same components and many other interactive toys that came before Furbys.
Many of the "fakes" on the "Furby Fakes" page shouldn't be on there as they could possibly cause problems for the companies making them.
(A simple renaming of the page to something like "Fakes and Furby-like toys" could solve this issue.)
However some are so obviously fakes!