If you killed all five major array hubs (they are named e.g alpha, kappa, omega), then yes, that is the end of the array loop. This is not the end of the questline - the finale is seperate, and is triggered after progressing through the vanilla questline (it should trigger after In Their Footsteps is complete for non-unity saves).
If you didn't kill the named array hubs and yet Harper is acting as if you did, this sounds like a bug some players have reported where the array hubs are prematurely dying. We have not been able to reproduce this ourselves yet on a minimal load order, and unfortunately all reports have either been on xbox or very heavily modded saves we are not able to open. If you (or anyone else reading) has hit this bug, and can provide a save file for us before the bug occurs and afterwards, we will dive right into it.