In statistical hypothesis testing, null and alternative hypothesis are statements about:

In statistical hypothesis testing, the null and alternative hypotheses are statements about population parameters.

A parameter is a fixed numerical characteristic of the whole population, such as its mean or proportion.

Sample parameters is not a valid term, since a sample yields statistics, not parameters.

Sample statistics are computed from data and used to test claims about parameters, but the hypotheses themselves are about the population.

The claim does not vary case to case, so a conditional reading of it is wrong.

A sample statistic estimates a population parameter, which is what the hypotheses actually concern.