A quick review of Oceania's current travel protection program shows several areas of weakness that should be considered when reviewing their plan:
Medical Protection: only $10,000 of protection. Granted it's excess over any other insurance that might apply however, many medical plans in the USA either don't provide coverage outside the USA or they restrict coverage because it's out of network. In addition if you're covered by Medicare you should also know that they don't cover you outside the USA. $10,000 of coverage is very limited especially if your current coverage doesn't apply.
Emergency Evacuation: only $25,000 of protection. That level of coverage might be appropriate if you were traveling within the USA but given the destinations that Oceania offers it is going to be very short in the event of a worse case scenario where actual cost can easily exceed $100,000 for a private air ambulance evacuation.
Pre-existing conditions not covered: there is no coverage if a pre-existing medical condition causes a medical expense loss or a trip cancellation or interruption claim. While pre-existing medical condition exclusions are common place, many travel insurance plans offer a "waiver of pre-existing conditions" if you buy the insurance within 10 to 21 days following your first trip payment and you are physically fit to travel on the day you're buying the insurance, and you insure your trip to value.
Better coverage is available. The earlier you shop for alternative coverage the better off you'll be because most travel insurance plans offer time-sensitive benefits that enhance coverage if purchased early.