According to the BABOK Guide v3, modeling of requirements can commence with elicitation results in any state. This means that even unconfirmed or preliminary elicitation results can be used to begin modeling, acknowledging that further elicitation may be necessary to refine and validate the models.
Reference from BABOK Guide v3:
" Elicitation Results (any state): modelling can begin with any elicitation result and may lead to the need for more elicitation to clarify or expand upon requirements. "
- BABOK Guide v3, Section 7.1.3 Inputs