I asked this on Reddit and figured I would here to. We just got implants on PS4. The Wiki says packs are awarded for completing novice directives. Mine are done already. Does this mean no directive rewards?
Since we're going by what the PC game is like: not retroactively, but the implants should appear in standard random implant pack rotation.
Sadly, you have missed the chance to get implant packs by doing the directives if you have already gone past the level at which they are awarded (lvl 1 for class directives and lvl 2 for objectives and leadership).