He's not the first Christian to hold such a role - don't recall previous presenters (not merely BBC TV's) having any problems despite sharing that particular understanding.
Where is the comparable prior situation? Or who, rather? Which "understanding" are you referring to? Creationism isn't an understanding; it's a belief. (And is the polar opposite of understanding, while we're about it). Theism itself isn't an understanding but a belief, come to that, as most vaguely sane theists are content to acknowledge. Where is the other TV presenter who thinks in the teeth of all scientific knowledge that the Earth was supernaturally created before the development of agriculture in the human species having to interview real scientists talking about actual science, as Walker will have to before very much more time has passed?
One could suggest that atheists should not be presenters because of 'some very sensitive interviews (they have) to conduct'.
One could suggest it, but it would be a quite remarkably stupid thing for one to suggest.