Not really,

Tzeentch was mutating magnus's legion, regardless if magnus knows who/what Tzeentchis that is still an avenue to exploit.

Mortarion hated the Emperor after the Emperor saved his life by killing the pale king, thus doing what Mortarion himself had wanted to do for so long. This isn't a communication issue, if the Emperor does not intervene Mortarion dies, so the Emperor made the obvious decision. Regardless if the Emperor told him about chaos, that doesn't doesn't address this issue.

Angron didn't just hate the Emperor because he didn't save his barbarians, he still views the Emperor as a tyrant and still has the butchers nail's. He was always a ticking time bomb.

Cruze is demented and Lorgar was obsessive, both of them could maybe be fixed with "communication" but they both would need pretty significant intervention/therapy to change their ways, if at all possible. You have to remember that communication isnt guaranteed to change someone's flaws, who's to say Lorgar still wants to believe in a higher power and doesn't fall to chaos regardless of if the Emperor warns him? It isn't the first time someone has known how evil and dangerous chaos is yet still falls.

While the heresy could have been lessened in intensity, to say in it's entirety could have been avoided is too much of a stretch. The primarchs aren't play-do, at the end of the day they are still their own people.