There's no downplaying the loss, but the good news is Rousseau is playing tremendous this year. That softens the blow.
You could argue that the defensive personnel this year is still better than what we fielded in the divisional round last year, even accounting for Hyde's and Miller's injuries. Rousseau and Edmunds have both taken a big step forward in their development. We added DaQuan Jones, a healthy Tre White, and better DE depth in Shaq Lawson. Ed Oliver has recently been playing the best ball of his career.
Again you can't downplay the loss of Von Miller but it's not an excuse if the season falls apart. The rest of the team is still plenty good enough to win it all.