Not true. Periods of abnormally low volume are normally the calm before the storm. Usually the move following a period of low volume is substantial. Lower volume during an uptrend usually indicates buyers are losing interest and lower volume during a downtrend means sellers are almost done selling.
There've been a ton of low volume phases in the last year or more. Lots of people wheel out the calm before the storm line then not a goddamn bean occurs for another few weeks or months. Sometimes low volume just means good old sideways and boredom.
Absolutely, which is why I try not to talk in certainties with my analysis by frequently saying "normally" and "usually." All technical analysis and volume analysis is merely speculation based on history and repeating patterns. The hope is to simply be right at least 51% of the time.