Migration to new GL and upgrade of release

Hello Gurus

I 'd like to know if I have to do a migration to new GL if I'm doing an upgrade of release from an ECC 5.0 to an ECC 6.0 EHP 6.

In the ECC 5.0 the New GL is already active without document splitting, If I upgrade to ECC 6.0 EHP 6 I will have to do a migration if I implement document splitting or not or I have to do the migration in every case.

Thank you in advance

Kindest regards

Giovanni