What I don't understand is how that could happen with a striker semi auto with a safety and a kydex holster with a completely covered trigger guard. Is the danger the striker trigger is under pressure and could release/malfunction and go off by itself or is the danger accidentally pulling the trigger on the draw or something(s) else?
For clarity, are you asking about a striker fired gun with a Glock-type trigger safety, or a striker fired gun with a thumb or grip safety?
For the typical striker fired gun with just the trigger tab safety, I suspect most accidents are caused during holstering as folks either forget to take their finger off the trigger or something gets in their holster and fouls the trigger, like a lanyard, or part of a cover garment. However, there is a video circulating showing a guy in a shop, where he bends over and it appears as if this drives his already holstered gun deeper into the holster and causes the gun to fire.
A thumb safety equipped gun, such as models of S&W M&P with this feature, or a grip safety equipped gun like the Springfield XD, if operated properly, should have less problems during reholstering or while holstered, than a gun without those devices.
There is a device for the Glock, the Striker Control Device (SCD or "The Gadget") that could help with the reholstering issue.
https://taudevgroup.myshopify.com
Separately, while I don't think there have been any AIWB incidents, there have been reports of SIG P320's and whatever the FN striker fired gun is (is there more than one?) where these guns have fired, while holstered, with a sharp contact to the gun causing the striker to release, and the firing pin safety didn't stop the gun from firing.