Not necessarily, and this catches out a lot of experienced travellers. A policy described as worldwide can still carry geographic exclusions, cruise restrictions, expedition exclusions, altitude limits or activity exclusions. UK government guidance on Antarctic travel warns about exactly this. Ask your insurer to confirm in writing that Antarctica, the Southern Ocean, and South Georgia and the Falklands where relevant, are covered.
The same warning applies to two things people assume are sorted. Credit card travel benefits often require the trip to be paid on that card and can carry low evacuation limits, no primary medical cover, no pre-existing condition protection, or explicit exclusions for remote expeditions. Annual multi-trip plans often limit trip length, trip cost, cruise travel, expedition activities or remote-region evacuation, and the word annual guarantees nothing about this voyage.
In both cases, get the full benefit guide and written confirmation that your actual itinerary and activities are covered, then compare it against your operator's requirement.