Withdrawals depend on your body being exposed to opioids over a period of time and making adjustments (receptor downregulation, reduced endorphin production) to counteract that exposure - then when you take the opioids away (or have them replaced with a partial agonist in the case of Suboxone/buprenorphine, or an antagonist such as naloxone) you experience WDs. Suboxone therefore shouldn't cause precipitated WDs unless you've been taking the hydromorphone for a while; however, if you take it while you are still feeling the effects of the hydromorphone you will be suddenly bumped down to sober pretty fast which would not be great.