Original: This was not due to a negation of the relationship between the two philosophers, however, but rather was the result of a suggested censorship by Heidegger's publisher who feared that the book might otherwise be banned by the Nazi regime.
Simplified: This was not due to diminishing relations between the two philosophers, however, but rather as a result of a suggested censorship by Heidegger's publisher who feared that the book may be banned by the Nazi regime.