The problem with this line of thinking is other parts, like Backstrom and Carlson, may fade earlier to the point where it has passed already and went unrealized. Not saying they're there but realistically it's very hard to make deep runs with multiple key players on the downswing and really none significantly on the upswing. Being prudent now may give them the opportunity to maintain a deeper pipeline but who knows whether it comes close to any sort of contending strength.
I don't disagree but I don't think that time is now. Or... it sort of is, and isn't, but the balance won't tip until Carlson finally does and I don't think he's there yet. It definitely won't look the same but in those positions they have slightly younger options in Kuznetsov and Orlov that have proven they can step in and produce, if not at the same level, well enough that reordering the depth chart isn't the same thing as missing one of the key pieces entirely.
Another Cup win is going to look from the outside like veterans making a last heroic push, and a lot more from the inside like a snake getting ready to molt as it pushes those parts to the fringe and leaves them behind. If anyone's ego is bigger than that the whole thing will fall apart, of course, but I don't see this many old players hoisting each other up without a lot of work from young legs and I don't really see the Capitals satisfying that condition without changing in the next year or two. That means accelerating and testing the guys they've been holding on to so far and then swinging hard the year after next.
To me that's the best window they've got, the season after next. You might see Backstrom as a specialized 3/4C or Carlson on the second pair but it's the only season with significant overlap between what they have currently and what they
need to look like other Cup contenders.