In the 80s, the bigger question for the Flyers was more missing Tim Kerr than the goaltending. They lost Kerr halfway through the 85 finals (he wasn't healthy anyways), and didn't have him at all vs. the Oilers in 87. They Flyers, already undermanned, were without their 50 goal scorer.
The question mark around Lindbergh would qualify more in the long-term picture. Do the Flyers still fall off the cliff in the early 90s if they still had Lindbergh?
Perhaps. Emery is nothing more than a substandard goalie himself, lackluster lateral movement - on that front, not too dissimilar to that of minor leaguer Michael Leighton. Slight upgrade in net in Emery, but I'm not sure if it would have been enough. Both with poor lateral movement and rebound control. That said, he probably doesn't give up some of the leaky first-shot goals that Leighton surrendered including the golden goal.
I've been through this argument a number of times, but I maintain that the Flyers could have gotten Dwayne Roloson and didn't pull the trigger, and made it look worse when they sniffed around other goaltenders, and traded Ryan Parent for
the rights to Dan Hamhuis, and were lucky to get a draft pick for him. The rumor was 2nd round pick, we had Ryan Parent and a 3rd to give. Leighton was playing well, but the Flyers needed the insurance because that season was Cup or bust despite struggling to make the playoffs (and before that comment starts a war, just look at the turmoil the franchise has been through since then). They dispatched the Devils, but I don't think they would have gotten so far behind the Bruins. Alas, that series did turn out to be one of our golden moments as a franchise, but its still a consolation prize.
I think it was the difference because it's not like Blackhawks boat raced the Flyers. The Flyers were rolling 4 defensemen in front of a replacement-level goaltender and found themselves in overtime of Game 6. They scored at least 3 goals in 5 of the 6 games, and lost 4 of them. In any other year, with a goaltender who is above replacement-level, that gets the job done.