The Prince of Wales has said that he wants to be 'Defender of Faiths' but I don't know what this will mean in effect. I suspect it would be rather in the way you describe.
Here is an article about it:

http://www.thecommentator.com/article/3594/inter_faith_coronation_is_contrary_to_church_of_england_teaching

That article is in response to this one:

http://www.telegraph.co.uk/news/uknews/queen-elizabeth-II/10066234/Next-coronation-to-involve-other-faiths-besides-Christianity.html

The decisions made will be interesting. I think we can safely say that the next Coronation won't be like the 1953 one in some respects.