On picture #1, there is no inductor, so there is no need for OSCON type caps. Inductor ringing and the ripple current thereof is not a big problem (there are other types of problems though, i.e ones associated with a DAC/ADC). I don't know much about a fully digital VRM design, so I can't say much.
In any VRM design, the primary consideration or indeed the major role is that of the ESR and the ability to withstand inductor current surges. Check any single or multi-phase buck-regulator datasheet and that is what you would see. While the chip caps may have a very high inductor current rating, there is no info that I can see regarding its ESR (looks higher from your datasheet) or its leakage current?
Will it work?...probably, but certainly not for the traditional reasons a VRM design doc specifies. I'm not trying to say you are wrong, I'm just trying to understand why this is a better option than OSCON? Perhaps this is because of the way I work. I always have to know why and fully understand what is going on before I start changing things around.
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