Realistically that probably involves getting younger and assuming some risk but finding equally versatile talents isn't easy. Finding franchises willing to get older isn't easy. MacLellan is more bold than GMGM but I'm not sure ownership is prepared to cut that deep. Overall I don't think they'll want to subtract a crucial piece from the room until they miss the playoffs and have more of a mandate. Even 92 is tricky removing his talent and not taking a step back. They could add a more consistent and defensive-minded center but finding the right blend to augment 19 and their wingers won't be easy.
Oshie may be the next one that needs to go, despite his leadership importance, due to age and declining pace. There will be a point where they're way too slow and it may be better to cash out on him rather than be stuck with an unmovable contract in 8/19's last few seasons. Not to say he should be exposed in expansion. They need to get strong value back. They'd suffer without him on the PP, in shootouts and in the room. They know they're going to get whatever he's got so maybe he also finishes it up in DC. I just don't know how they can manage an increasingly slow core. Sprinkling in a McMichael or Fehervary isn't enough. It's also an area where Mantha doesn't help a ton. His hockey sense is top-notch and he's defensively strong but he's never going to be a burner. He can work with them but without anyone opening up space can it work? It's an area where Wilson perhaps more than anyone didn't impress in the playoffs. That should have been his bread and butter time to shine and he still very much looked like someone afraid of crossing the line.
My idea has been just upgrading the second D pair to offset a fundamentally declining offense but there are no easy answers. More pace and skill from the back-end could help the aging core and to further accentuate Laviolette's approach but those types of defenders are rightly highly valued. They're not exactly asset rich, particularly if not prepared to substantially subtract from the roster. There are no quick fixes in reaching that top level. They're just going to have to hope injuries were a key reason, that some of their older dogs can both learn some new tricks and turn back time and that they can once again get back to drafting and developing integral pieces that can infuse them with hunger and pace.
It's a matter of asset management to me.
Maybe I'm way off and Wilson wouldn't return much in a trade. But from every report and snippet of every interview it seems like Wilson is the type of player other GMs would kill for. He's already significantly impacted the Penguins franchise and perhaps even the Rangers now. Why not leverage that apparent value in an attempt to significantly improve the core in Washington and make the team better? As you mentioned, despite Wilson's outsized presence in media circles and his "rent-free" status his value hasn't really been apparent in the postseason of late. He's largely been invisible when it's mattered.
And why not leverage Carlson's status as a #1 RD to get someone to actually put the team over the hump in the postseason? It's going on 3 straight postseason duds for Carlson where he's actively hurt the team, yet I'd be shocked if his value isn't still really high given his Norris contention, point totals, and his perceived status around the league.
The problem with just hoping injuries were a key factor is that even if they were, Ovechkin, Backstrom, Oshie, and Carlson are all going to be yet another year older next year. We need to bet on a rather unlikely parlay in order for them to succeed next year, namely that they will all remain mostly healthy and that their skills won't have deteriorated much due to aging yet another year during a period when most players' decline is rather steep even if healthy.
It's not a bet I'd be willing to make, and that's why I think the more prudent path is to actually add someone to the core. I don't think just upgrading the second pair does much to move the needle if John Carlson keeps playing the way he has for 3 years, for instance. I don't think the Vrana and Mantha swap really accomplished enough to make them contenders. They need a real impact player or two.
As I mentioned I think ownership can be persuaded if management approaches it as not just as a way to try to win another Cup, but as a way to get Ovechkin to 895. As it stands I don't see a path for Ovechkin getting that milestone. But with someone like, say, Jack Eichel centering him for the next 5 years? It's possible. And imagine the media spotlight and more importantly to Ted the $$$ as Ovechkin chases down Gretzky.