Hello! In short, no. As Arthurian legend was developing, no King of England believed that Arthur was actually going to return. In fact, Anglo-Norman chroniclers commenting on the rise of Arthurian legend ridiculed the notion of Arthurs messianic return. Henry II also made a big spectacle of rebuilding Glastonbury Abbey after the discovery of the supposed tombs of Arthur and Guinevere. It is speculated that this "discovery" which is not corroborated by modern archeology or any other documentary evidence, was to drive the point home that Arthur is dead and not coming back and that any notion to the contrary was nonsense.

I have written extensively about medieval receptions of Arthur that touch on this topic:

Geoffrey of Monmouth first writes about King Arthur as an historical personage. To what extent did people during the middle ages think Arthur and the Knights of the Round Table were real historical figures? When did that perception begin to change?

How was Arthurian legend viewed by people during the 12-15 centuries?

When/why did the Arthurian myths shift from being Welsh to being British?