With most teams in the process of coming to terms with their restricted free agents, its worth taking a look at some of the cap situations around the NHL. The Devils have already made one transaction this summer where they took advantage of another team's cap situation when they acquired PK Subban from the Predators, so its not out of the realm of possibility they're looking to strike again, especially since they'll still have cap space to make a move once they agree to terms with Butcher and Zacha
Teams currently over the upper limit of 81.5M - NY Rangers, Toronto, Washington, and Pittsburgh.
As it has been discussed in other threads, the Rangers have obvious moves to make to get under the threshold, whether its a trade of Vladislav Namestikov or Ryan Strome and/or a potential buyout of Kevin Shattenkirk, Marc Staal, and/or Brendan Smith. Toronto's cap space, or lack thereof, will eventually go to Mitch Marner, whether its on August 1st or December 1st. Washington and Pittsburgh are more interesting in that they don't appear to have an obvious trade candidate on their roster, but they obviously need to do something to get under 81.5M
Teams with under 5M in cap space, but notable RFAs remaining - Dallas (Honka?), Vegas (Gusev), Edmonton (Puljujarvi), Calgary (Tkachuk)
Obviously, Vegas won't have a shortage of suitors for Gusev should they decide they can't afford him, and obviously, the Devils should be at the front of the line should he become available. I'm including Puljujarvi here as he's been vocal about wanting out of Edmonton and may be a worthwhile gamble on a former 4th overall pick. Calgary won't trade Tkachuk, but they may need to deal someone like Frolik to fit Tkachuk in and there was that rumor earlier this offseason that the Devils were talking about him, so it needs to be mentioned.
Other teams with significant RFAs remaining and their cap space - Vancouver (Boeser and 5.05M in space), St. Louis (Barbashev/Edmundson - 5.07M), Tampa Bay (Point/Erne - 5.5M), Boston (McAvoy/Carlo - 7.29M)
Some of these might take care of themselves, some of these might drag into the season. I don't think my opinion on Tampa has changed in that I would take Palat or Killorn in a trade if he'd waive his NTC. I wouldn't touch Backes under any circumstances, although I'm sure Boston would love to unload him.
In summary, I do think there will be an opportunity somewhere for Shero to potentially add a piece once the dust settles with the RFA signings. But I do think most of the teams I pointed out above will have to do something.