No a player's contract has virtually no impact on the value of the franchise itself. But if you don't care about spending beyond bare minimum money with the goal of winning "more" major league games, and you're happy to pocket every penny you possibly can in the near-term, it certainly doesn't hurt to keep the slate as clean as possible for the next ownership group. It can be more appealing to some to know that they come in with virtually zero long-term salary debt commitment that THEY had no hand in agreeing to.
So I think there's some merit in this and we see that manifest in the Nationals right now. They have a ton of dead money on the books right now. 2023 is year 2 of 7 they are paying Max 15M in deferrals from his 7/210 deal. Strasburg is the worst contract in MLB. He signed that massive extension, has pitched 31 innings over 3 years with an ERA over 7 and has 4 more years left with 80M deferrals into the future. Corbin has 2 years and 57M left and he's been bad the last couple.
Those contract don't impact the sale of the franchise, but they are consequences in what the new ownership group will be willing to do near-term. Each year they burn before sale is a year this load comes out but mostly just in terms of the short-term outlook. They generate a ton of revenue each year which covers all of that and much, much more. Lehner's aren't stepping out to invest, they'll "rebuild", lower expectations and sell the same BS many ownership group do and let the contracts wash out while they build some resources on their way out. They'll still do stuff, because unlike the Orioles, they aren't trying to scuttle their franchise value. Nationals sort of need someone (like a Mike Elias) to rebuild some of their internal processes because their development system has been trash. They are on the verge of competing for that #1 MiL system so it'll be a good opportunity for an exec who likes that. Won't be Dombrowski (he's doing ok in Philly anyways).