When I ran the Dragonlance Chronicles several years ago, everyone chose to make their own characters. Our party was a grim paladin who was the "blue crystal staff prophet," a wizard who primarily used his spells to blast and punch people, a renegade Silvanesti elf fighter and former Dragonarmy officer, and a goblin necromancer who secretly worshiped Chaos.
We were using the 13th Age rules, which allowed for more unconventional character concepts and easier reskinning of abilities.
I did DM the Chronicles for a group back in high school, and while my memories are blurry I do know everyone chose to use their own characters as well.
In both instances only one player was familiar with the novels, so the original Heroes of the Lance as pre-gens didn't hold great significance to them like they would for fans of the setting.
Sorry, I was not clear - I thought the pre-gens were fine, but the ADVENTURES were not very good.
They did punch above their weight class, but the party was a bit imbalanced in that the majority were Fighters. They did have an obligatory Magic-User, Cleric, and Thief, but other than DMPCs joining later on about half of the original Heroes were pretty interchangeable as "fight with sword, fight with bow" types. This was mollified a bit in 3rd Edition, with Riverwind being a multi-classed Barbarian/Ranger and Flint being a multi-classed Fighter/Master (expert craftsman), but even then it wasn't a very role-diverse group.
That may have also played a factor in people not sticking with the pre-gens besides the fact almost every gaming group prefers their original characters.