If Seattle's deciding between DeBrusk and Ritchie, they will take DeBrusk with little to no thought. And if it's between Ritchie and Lauzon, they take Lauzon.
Ritchie does fill an element, and right now, DeBrusk doesn't and they both occupy the same spot on the roster: third line complimentary left wing. But you protect DeBrusk as he'll have more trade value on his own.
DeBrusk's only future with the team is either displacing Ritchie for that 3LW or taking the off-season to convert to 2RW (I'm assuming Hall & Krejci return). He can't play 3RW because while having a different skill set, he's a complimentary player like Ritchie and they both can't be on the same line together.
That's a rational idea, but again, there is no way to state that unequivocally. Too much in play to be able to be so definite. Agree with the remainder of your post- Richie meets a team need that would be very conspicuous by its absence whereas Jake, well, not so sure you can say that.