Well you are certainly correct that after the Norman conquest Germanic mythology came nowhere close to the importance the Arthurian mythos had in English culture. Heck even straight up Gaelic myths were probably more important with the influence Macpherson's Ossian had (almost like a lesser second European-wide mythological cycle of Celtic origin in similar vein to the Arthurian.)
From what I understand the real big revival of things Germanic and Norse starts with Wagner, though Wagner himself was infatuated with things Celtic and Arthurian a la Lohengrin, Parsifal, and Tristan & Isolde.