of course, if warlocks dont auto pass the test, for the purpose of allowing DtW
then they dont get to resolve the power either,
since
BRB pg 68
assuming that the Psychic test was passed and the enemy did not nullify it through a successful Deny the Witch roll, you can now resolve the power
the same trick of the language that is being used to deny DtW rolls, also deny's resolving the power, as BOTH steps stipulate that "the psychic test was passed"
so you cannot pick and choose, and say passing the test only applies to DtW and not to resolving the power as well.
if you must pass the test to result in DtW, you must also pass it to resolve the power, both requirements state the test must be passed,
so there are only two options
1: warlocks cannot cast powers, because they never pass a pyschic test (which also prevents DtW roll)
2. warlocks ALWAYS cast powers, they are always on, because they auto pass/ignore tests in ALL steps of the power resolution process
one cannot say they treat psychic tests one way in step 4 of the psychic power process, but they treat it completely differently in step 5