Interesting concept.. I think I would still prefer to do my way... using Report Builder and live-linked graphs from Excel to Powerpoint... if only cause then all my styles stay consistent. If I notice an issue with values, I don't have to redo all the work, and I don't really need 1 visualization per slide for some of my stuff.. so having to re-size and move visualizations around in PPT each time is a lot of extra overhead. My current method, once the style is set up, it's done... it just needs a Report Builder refresh and a link update in PPT and it's good to go (I even live linked slide titles with dynamic text for the Data Ranges).
This is still really good for people that don't have that advanced set up
But it would be nice to see if this can get to a stage where you can curate how large the visualizations are, where they sit on the slides, and choose visualizations to show on the same slides together so that some of than manual cleanup and organization can be automated.