'Formal roles' is a distinction without a difference. There have been different classes with different roles throughout D&Ds history.
Yes, 3e first formalized them as iconic class roles, and 4e first formalized them independent of class. In between MMOs adopted formalized roles - in immitation of D&D!
Roles are nothing new, only the labels are new. To argue otherwise is absurd - and, really, whats the purpose of doing so, anyway? If you get role excised from the game, you'll still have characters who are tanking, healing, blasting, and so forth, anyway, it'll just be a tad harder to explain to new players, and require a little more circumlocution to pull a decent party together.
This whole thing smacks of rejecting a concept /only/ because it's found in 4e.
I disagree.
Early D&D had no roles except healer, blaster and meatshield. The thief was there to deal with enviromental hazards like traps and locks and was usually considered the most disposable 'role' in a party IME.
There was no explicit controller, although either the Mage or Druid could serve as one with the right spells. There was no explicit defender although a Fighter or Cleric could tank if needed. There was no striker at all, although a high level mage was unquestionably the big guns of the game. We called him a blaster.
There was no leader, that term did not exist until 4e invented it as a fig leaf to cover the term "healer".
3e formalized the Fighter, Wizard, cleric and rogue as the iconic 4 classes. That's not the same as roles. They upped sneak attack damage to make the Rogue more attractive which led to his serving as a striker, and led to later "Glass cannon" variants like the Ninja.
There was no such thing as a leader in the 3e lexicon. There was a non-critical job as a buffer. That role could be filled by a Cleric or Bard or possibly a Mage. Later the Artificer.
There was also a Healer. This was a Cleric or druid or maybe a Bard. Later there was the ... Healer.
3e design space was not constrained by roles and was richer for it. Totemists, Binders, Monks, Bards, Druids, Beguilers, Duskblades, Dragon Shamans, Warlocks, Sword Sages.
You could generate some pretty good arguments trying to pidgeonhole those classes into a 4e style role. Does that make them bad classes?
Again, the 4 explicit roles are straightjackets that suit one specific style of play under a specific set of circumstances. Outside of that "Kick-in-the-door" tactical map dungeon crawl they are nothing but a hindrance.