The Bug

Deep Ocean & Ocean is not needed for Adventure Time, however it does generate naturaly.

Reproduce

• Do /advancement grant @s only adventure/sleep_in_bed
• Look at your adventuring time advancement
  You should have one biome (your spawn biome)
• Do /locatebiome deep_ocean or /locatebiome ocean
• Teleport there
• Look at your adventuring time advancment
  Notice it is still on one biome

Expected Result

Deep Oceans & Oceans would be apart of the "Adventure Time" advancement