A Brown buyout looks bad on paper. The cap hit only goes up before it goes down, and then it doesn't come off the books until 2027 if they did it this year. For what, a couple million in cap space? At this point, I'd rather they just run out Brown's contract, and if it helps them get a higher pick every year until then, then in theory at least that should help down the road.
Gaborik's salary is still $5m next year, $4.5m after that, and doesn't drop below $3m in the last years of the deal. That's a lot of money to walk away from, even if he has a lot of money from previous contracts. He could play 35 games a year and get all that money. Outside of a career ending injury, they can't just put him on LTIR forever either.
They could buy out one or both, and it would help in the next couple years, but then they would pay for it for a while. If they had something in mind for next season, or two years from now, maybe it would be worth it, if the team was good enough to win the Cup again. If they're not good enough, then in 4 or 5 years, the buyouts kill the team, and then there's another half decade of completely dead, or just mostly dead, cap space. Have fun stormin' that castle.