The wisdom became "Don't build your business on another one." and twitter was the primary example of why not. For twitter to turn around and say "Ok, we made some mistakes, and we want to develop that trust again." is misunderstanding what happened.
twitter changed the conventional wisdom, not just wisdom about twitter.
That wisdom is WAY older than twitter. It may have become a fashionable meme again because of Twitter, but platform risk has been around probably about as long as computing. Certainly the idea goes back at least as far as the infamous DOS/Lotus 1-2-3 dustup. Google "DOS ain't done till Lotus won't run" for example. Note that whether or not Microsoft actually tried to break Lotus 1-2-3 isn't the point. I'm just saying people have been aware of, and talking about, these kinds of risks for a LONG time.
"The pattern has repeated itself more times than you can fathom. Startups rise, evolve, advance, and at the apex of their glory they are extinguished. Lotus were not the first. They did not create the Platform. They did not forge the APIs. They merely found them - the legacy of my kind." - Twitter CEO in my twisted imagination.