No, the court for whatever reason did not like that hearing date. Perhaps the judge has that day off or other cases. Only the hearing date is reset, not the paperwork that you filed. You should not refile any papers. The moving party may still have the opportunity to file a reply brief.
No. The judge merely rescheduled the hearing. The motion to compel remains pending for decision.
The fact that discovery was provided before the initial hearing date will, however, be relevant at the hearing and the parties will want to make the judge aware of this fact. This is especially true if the discovery provided covered all of the items sought in the motion to compel because judges do not like preparing for hearings when the parties no longer have a dispute.
No, nothing has to be re-filed, it probably means that the judge or the judge's staff has a time/date conflict and they needed to re-schedule the hearing.
When a party provides discovery responses before a motion to compel is heard, it often influences the judge to not grant the motion or sanctions to the moving party since the objective was accomplished.
Disclaimer: Please note that this answer does not constitute legal advice, and should not be relied on, since each state has different laws, each situation is fact specific, and it is impossible to evaluate a legal problem without a comprehensive consultation and review of all the facts and documents at issue. This answer does not create an attorney-client relationship.