Complex sentence: If the final two games ultimately go as predicted, then the chance at a bye week or the risk of elimination disappears, so those games need to be played last so there is never a situation where two teams know that their result would certainly not matter.
Split into simpler sentences: If the final two games ultimately go as predicted, then the chance of a bye or the risk of elimination disappears. Therefore, those games need to be played last so that there is never a situation where two teams know that their result would not matter.