410(b)(6)(C) transition period

[Guest usafa89]

Plan is in 410(b)(6)© transition period following closing of acquisition. It wishes to maximize the transition period, but also wishes to amend its 401k plan to add an auto enrollment feature. The addition of the auto enrollment feature will allow the plan to be considered a safe harbor plan (it already has a level of matching contributions that meets the criteria). Would this amendment be considered material so that it would disrupt the transition rule?