What did your TA say? Below are the requirements from the RCL TA Website and it clearly states that vaccinations are required for Transatlantic sailings:
Vaccination Requirement
COVID-19 Vaccination Required for Guests Age 5 and Older
Transatlantic Sailings from Europe
Testing Requirements
Testing Requirements
All guests age 5 and older must bring a negative test result for a COVID-19 test taken within 2 days before boarding day.
The test you take must be supervised by a health professional, such as a doctor, pharmacy technician, public health worker, or telehealth professional. Telehealth testing at home is accepted for vaccinated guests, and must be conducted under live video supervision. Tests must be arranged on your own and are at your own expense.
Guests age 4 and younger do not have any testing requirements.