John Forrest writes in The History of Morris Dancing 1458-1750 (University of Toronto Press, 1999, p. 251):

The two classical episodes [i.e., the stories of Bumpkin the huntsmen and Hobbinal the shepherd] have rural settings and are heavily larded with country customs. The tale of Bumpkin, for example, contains the famous maypole song 'Come you youngmen' as an entrance piece for a chorus of huntsmen and country lasses, and a general country dance, along with other presumably more conventional stage pieces, including a huntsmen's dance and a dance of nymphs. Incidentally, the maypole song was set to the tune 'Stanes Morris' (see chapter 9) by William Chappell in the nineteenth century on the grounds that the two fit so well together, and for no other reason (Chappell 1859, 125-6). Yet, since Chappell's serendipitous experiment, almost universally, secondary sources have uncritically taken the match to be historically legitimate (see for example Dean-Smith 1957, 73, for a discussion), thus asserting a spurious equation between morris and maypoles. There is no evidence that the words and music were ever performed together before the nineteenth century.