Bundle will be down if you do not add a unit to the ae interface even with child links being up.

We will not see any LACP statistics if no unit is added to the bundle.

AE will not come up.

We will need to add unit 0 to be able to bring the bundle up due the following statement:

The logical unit 0 is used to send and receive LACP or marker protocol data units (PDUs) to and from the individual links.