Depends on whether it's representative of what's going on in the ring land area or not (which is an area of even higher heat and lower flow).
The problem with varnish is that it's a precipitate. Oils are blended with dispersants and detergents to both prevent agglomeration of deposit-forming contaminants and to keep them in suspension. If they are plating out, it means the additive package isn't doing its job in this department, likely due to being saturated/overwhelmed.
So, if the oil is no longer able to keep this material in suspension, and we are seeing it plate-out in areas of low flow (like the top of the heads and on other surfaces) then the same thing is going to be going on, but in a more concentrated form, in the ring land area, where flow-through is extremely low, and the conditions are more conducive to lacquer plating accruing. Once sufficient lacquer/varnish is accumulated in the rings, particularly the oil control rings, they can start to stick. This causes problems with oil control, and the byproduct is consumption. When this starts to happen with the upper compression rings, you get increased blowby, which in turn increases the volume of contaminants entering the oil, expediting the rate of degradation. This also causes loss of power. None of this is desirable, but it's natural to see some degree of it on high mileage engines run on "regular" oils.
