We have a single forest with 2 domains. I'll call the domains CompanyA and CompanyB. We have Exchange 2013 installed in CompanyA domain providing email for both domains. CompanyA has been purchased by a third company and we need to separate the companies. We will be migrating CompanyB to it's own AD forest. We also plan to implement Office 365 for the approximately 250 users in CompanyB but want to keep our on-premises Exchange organization in place for CompanyA. I would prefer not to implement ADFS and would prefer to use ADSync and Password Sync. I understand that I won't have SSO but will have same sign on.
My question is, can I setup ADSync and password sync to only sync the users in CompanyB domain to Office 365/Azure Active Directory?