Yes, Vybrid itself takes care of its 1.2V power rail, the only requirement being to NOT connect an external 1.2V source to it (i.e. following our datasheet and reference design).
Just an example of how the designer can violate this rule - if the capacitance on the 1.2V rail is too high (way higher than recommended in our documentation), then when powering down, the actual rail voltage might be decreasing so slowly that at some point would appear to be higher than that of the 3.3V rail one decreasing faster.
