how sure are you that whole brain emulations would be conscious

The question is ill-formulated; everything depends on how we resolve this point from the LessWrong WBE wiki:

The exact level of detail required for an accurate simulation of a brain's mind is presently uncertain

For example, one "level of detail" hypothesis would state that everything about the process matters, right down to the detailed shapes of electrical fields in synapses, say. Which would probably require building synapses out of organic matter. Which brings us right back to the "biological" view.

This post by dfranke raises similar issues (question #5), and I regret that I have only one upvote to give it, and to give yours.