Certainly, at this early stage anything could change, so even if this is being considered in may not end up happening, and one assumes it will be done with flashbacks if it happens at all.
And it really does seem like anything could happen in the new films.
One early report has indicated that actors like Alec Baldwin and Henry Cavill, both of whom are currently dead in the Mission: Impossible franchise as far as we know, could make appearances in the new movies.