I love this question, and there is a number of things to unpack.
Exactly where we are measuring a pressure in that circut matters. We usually measure a persons BP in the brachial artery, so relatvely on the left side of your picture.
Here, we can consider the pressure to be part of a simple circut, where Pressure = Resistance * Flow (ohms law).
Vasoconstriction of artieroles further downstream could be considered to be increasing resistance. This results in an increase in pressure at the level of the arteries and specifically, where we measure it at the brachial artery.
(As a side note: it doesnt overly matter at this level that the distal system is in parallel. For simplicity, vasoconstriction will still increase the overall resistance. In a parallel system, increasing all or most of the resistors still increases the overall circuit resistance)
If we were to look at what is happening in the microvasculature, its a very very different kettle of fish, and much more akin to what you are describing with Bernoulli's principle.
In areas subject to vasoconstriction, there is indeed a decrease in pressure. This means there is less perfusion at that area (due to a decrease in hydrostatic pressure, see starling forces).
In areas not subject to vasoconstriction, there is a relative increase in pressure and therefore an increase in perfusion.
This about why this matters - We want to keep perfusion high in places that need blood (the brain, the kidneys), so they will stay relatively dilated. Conversly, if we dont need to perfuse our muscles, we can direct blood away from them and perfuse other organs preferentially by constricting their blood vessels.
Its probably worth noting as well - the resistance happens PRIOR to the capillaries. Capillaries dont change size. The artieroles and meta-arterioles do but the pressure before and after them does change and the pressure will be lower in areas that have undergone constriction.
To make matters more complicated however (read on at your peril);
If we also apply Ohms law at the level of the microvasculature and we consider this to be a parallel circuit, consider that increasing resistance will also lead to a decrease in flow. This is "shunting", where blood will flow preferentially to areas of less resistance. This extra flow 'would' (with an ideal fluid and non-compliant vessel), increase flow and decrease pressure. However, blood does not behave like an ideal fluid, and its viscosity prevents its speed from increasing as you'd expect. Moreover, the blood vessels tend to expand with the increased blood volume, increasing the radius of the vessel which significnatly decreases speed and overall actually probably increases its pressure (since radius is SUPER important in determining speed).
NB: This is STILL a huge oversimplification of a complex physics system - we havnt even touched on the effect of gravity and columns of water (is the perfusion pressure in our feet HUGE??!)