Clapper's note "reaffirmed the intelligence community's longstanding commitment to speak truth to power".  Clapper's statement of his purported principles certainly is not borne out by his past actions, i.e. denying that the US Government illegally accessed and acquired the  communications of US citizens, and repeatedly stating that Iran was nowhere close to having a nuclear weapon capability.
Judging by Clapper's action, his statement of principles really means "the intelligence community's longstanding commitment to say whatever President Obama wishes.  And, presumably, it would have applied to whatever a President Clinton wished.  But, clearly, it doesn't apply to whatever President Trump wishes.  That would offend Clapper's principles.