I'd go even further and mention that if the decocker on the P99 is pressed, and held into the slide, it physically blocks the striker from impacting the primer on a chambered round. It is not a "striker control device", but instead, it is a "striker block", in that the trigger can still cock and release the striker, but the striker will stop before the impacting the chambered round if the decocker is pressed and held into the slide while holstering.
That being said, I'm not a fan of AIWB. Something about pointing pistols at femoral arteries and reproductive organs while holstering steers me away. There are workarounds, like removing the holster first, but that is not a practical way to practice on a shooting range, for real life. It surprises me that the same guys who are against manual safeties seem to forget most of their arguments against them when it comes to AIWB.