From the AVMA:
“Reasonable Assurance is not a preaccreditation action by the Council and does not confer accreditation of any kind on a developing college. Reasonable Assurance may lead to Provisional accreditation if a developing college is established according to plans presented to the Council, and if these plans demonstrate intent and a realistic plan to comply with the Standards of Accreditation. Reasonable Assurance may be renewed annually by the Council for a maximum of three years based on progress documented in biannual reports. If a developing institution granted Reasonable Assurance fails to continue to demonstrate that its plan to develop its program will comply with the Standards, or if the program significantly changes its plan without notifying the Council, the Council may withdraw the classification of Reasonable Assurance. A college granted Reasonable Assurance must offer admission to and matriculate its first class of students within three years.”
So basically, it means that the school is at a place where it’s likely it has what it needs to become accredited eventually. However, they have no students so it’s impossible to evaluate that aspect. This allows them to matriculate students in order to prove that they meet the standards set forth by the AVMA COE for a functioning vet school. If the school fails to meet those standards, then they lose that reasonable assurance. If everything goes well, then they get provisional accreditation (which is what I’m sure you meant when you said probationary). If things go well after that, they become fully accredited.