The answer is "it depends."
For example, if the previous owner did not release that Mac from Activation Lock, or if a Firmware Password had been set and not removed prior to transferring ownership, or if is remotely managed through an organization such as a business or educational institution, then you will be unable to use that Mac either now or at some point in the future.
Are you certain that Apple Support document was complied with? How do you know? Do you know its previous owner and are still able to contact him or her? The answers to those questions will address the uncertainty you express.