With Robert Brandom (and for recognizably Hegelian reasons) I think that Whig histories are necessary. I also agree with conservative critics that American English departments damaged their own enrollments when the 1980s attacks on the canon led to too sweeping curricular changes. In every field, it's very important for students to master a Whig history that allows them to critically engage with contemporary work and that gives them an analogical jumping off point to apply their knowledge elsewhere. And students know this.
I also agree about 90% with Brandom on how this Whig history should be put together for philosophy. A philosopher must understand Kant, how Kant led to Hegel, how (and hopefully why with respect to the 19th century) Hegel was finally suppressed in the "back to Kant" movement, how phenomenology and logical positivism pushed the neo-Kantian moment to its breaking point, and how contemporary philosophy is a reaction to the agonies and ecstasies of positivism and phenomenology.
But as helpful commentators (Peter Gratton, Robin James, Ed Kazarian, Carl Sachs, James K. Stanescu (AKA Scu), and various anonymous people) pointed out in this thread's discussion, the Brandomian Whig history is populated exclusively by white males, which is extraordinarily problematic for reasons adumbrated there. What to do about this?
The reason I'm loathe to mess too much with Brandom's Whig history is that people who are ignorant of large chunks of it often end up just repeating certain moments in it.* I'm also very loathe to get rid of the idea of Whig histories all together. But maybe Carnapian tolerance should be the order of the day here, letting a thousand Whig histories bloom? Or maybe the idea of a Whig history is so shaped by exclusion that we really need to try something else. To their detriment, I don't think English professors figured this one out, but we're philosophers and can possibly do better. I don't know.
*Indeed, people (myself included) have argued in print that Brandom himself has not properly absorbed the early critiques of Kant and later critiques of Fichte that paved the way for Hegel, or the context in which Heidegger was led to write about animals in the boredom lecture. But the very fact that we criticize Brandom this way shows that Brandom/Hegel has won in with respect to his main meta-philosophical contentions.]