In both cases BP falls.
All disorders that result in a fall in BP are addressed by "so-called compensation" on the part of the circulatory system as if the cause for this drop in BP was due to blood loss and reduced preload and the development of shock.
The response the circulatory system introduces, for a true case of shock, is intended to support the circulatory system for a time period measured in hours.
The so-called shock response was never intended to support a circulatory system in need of support for a time period measured from days to years.
In the setting of heart failure that results in a fall in blood pressure, the "Shock Response" is activated for a period of days to years.
How is sustained activation of the RAAS detrimental?
Increased thirst is detrimental because it increases preload which promotes further pulmonary edema, pleural effusion, ascites, and organ edema
Thus sustained activation of these "so-called compensatory" measures accelerates the demise of the patient with a dysfunctional heart as the cause for the reduction in BP. Thus activation of the shock response for a time period measured in hours is supportive. Activation of the shock response for a time period measured in days to years is detrimental.