I would call this a slide show not powerpoint mostly because making it work with the satanic office formats is a path to hell.
Hopefully simpler formats like this will become the norm and the old ones can die.
The term "powerpoint" has been genericized in the common vernacular to mean any electronic slide show, like kleenex for tissues and sellotape/scotch tape for transparent adhesive tape.
It might not have reached legal generic status but just about any working professional will understand what you mean if you refer to "making a powerpoint deck" even if you don't use the actual Microslop product.
You are right, but I guess a lot of people recognise PowerPoint as a brand. Maybe I can bill this as better-than-powerpoint!