Sabres fans will think it's a joke because they overrate their prospects and think they're all elite. But, this proposed offer carries more risk for the Flyers, tbh.
Laughton is a very solid two-way center who happens to score big goals at opportune times. He's in the Mike Peca mold, albeit not as good as prime Peca. But Laughton is a great character guy and leader. He's the exact type of player the Sabres could use with their young core.
Farabee is a decent-sized winger with some jam. His offense has declined a bit but he is skilled and likes to battle. Again, another type of player the Sabres could use.
Zamula is a nice, reliable D with good size who could be spotted on PP2 for the Sabres if needed.
In return, the Flyers get Byram, who is a very nice puck-moving D. Yes, he is a tad redundant with Drysdale, York, and Andrea, but he has skill and the Flyers still need to find the right type of player to click on the PP point... Drysdale hasn't been it, unfortunately. The issue with Byram though is, like Drysdale, he tends to get dinged up a lot.
Ostlund is a nice prospect but he's an unknown at the NHL level and the Sabres are loaded with smaller, skilled youngsters... Peterka, Quinn, Benson, Kulich, Rosen, Helenius, etc. ... and they can't play them all. At some point, they need to move a couple of them for proven assets who can bring other elements and intangibles to the ice... not just flashy prospect highlights.
If Ostlund doesn't pay dividends for 2 more years, the Flyers are giving up 3 proven NHLers for Byram. And the Sabres definitely take the next step.