If the CPI prints another small decrease during the next report, both legacy and cryptocurrency markets could surge to new all time highs. But to play the devil's advocate, isn't the sudden change of mood to extreme bullishness also inflationary?
A decrease in CPI prints has its own advantages and disadvantages. Looking at it closely, a decrease in CPI prints will benefit the consumers. CPI prints decreasing will allow consumers to buy products and services at much lower prices.
CPI prints can actually be used to assess which investment one can make. But like you said if it decreases too suddenly, it might not be as beneficial as it looks like.
More purchasing power will result in higher demand and if the supply can not keep up it might inflict inflationary tendencies.