On a ketogenic diet causing an increase in uric acid causing vasoconstriction and elevated blood pressure--the evidence in people actually eating a ketogenic diet goes the other way, it's more common for blood pressure to go down than up. In fact people on blood pressure medication need to be careful, they can end up overmedicated due to this.

Uric acid might raise blood pressure, all else being equal--but there's so much else going on metabolically during the shift to a ketogenic diet that that's normally irrelevant.