Pax... my guy, are you basically suffering from memory loss or you read a whole ass different copy of Bleach that we didn't read?
Him being able to affect Ichigo's Bankai with The Almighty =/= being able to effect Frieza with The Almighty. Again, if Yhwach could do anything like he did to Ichibei and Ichigo's Bankai, why NOT kill Ichigo with it? And it wasn't like he was doing so... so please tell me.
Also, Yhwach does not create new futures nor does he "fuck with probability", he literally brings forth a timeline that can happen into the future. That is literally how his powers work.