In Inga-Stina Ewbank's essay "The Triumph of Time in The Winter's Tale" (Review of English Literature, 5 (1964); reprinted in Shakespeare: The Winter's Tale. A Casebook, edited by Kenneth Muir, 1968), I encountered the following passage:
Critics of the myth-making school read these lines as a confirmation of the essentially mythical nature of the play: there, they argue, is the first direct sign of the regeneration of the King.
Ewbank does not reference any examples of scholarly publications, nor does she mention any critics that would belong to this school.
According to Cindy M. Okamura, Myth-Criticism
is an interpretative approach to literature which may be used in conjunction with other approaches and reading techniques. A myth-critical approach generally uncovers or identifies manifestations of mythology in a literary work--whether as the creation of an original myth, as the appropriation of a traditional mythological figure, story, or place, or in the form of allusions--and uses these mythological elements to aid interpretation of the work.
According to Caroline Hagood, writing on the Kenyon Review Blog (What the Heck is Myth Criticism?, 06.12.2019),
Myth criticism would best be applied to writing replete with archetypes, such as Alfred, Lord Tennyson’s Idylls of the King, for instance. Tennyson’s work is rich with both myth-making and mythic archetypes, such as the wise seer, Merlin, who is “bard, and knew the starry heavens; / The people call’d him wizard” (Merlin and Vivien).
Myth criticism applied to The Winter's Tale would discuss mythical aspects in the play (there are many references to Greek and Roman gods such as Apollo and Proserpina) and the significance of winter and spring in the play. However, this does not explain what the "myth-making school" was, especially in the context of Shakespeare criticism. If there is such a school of Shakespeare criticism, who were its founding and/or leading figures? Did they publish any interpretations of The Winter's Tale?