CRM does not map to CRM Plus

CRM does not map to CRM Plus

I was looking to upgrade some of my users to Zoho CRM Plus.  They are currently using Zoho CRM.  But I have been told by my account manager that 'The CRM data within your current Zoho CRM subscription will not be mapped to CRM Plus.'  So what's the point of me upgrading?  I need the data in my current CRM to utilise the other apps in CRM Plus. (for example using Campaigns to send emails to my client base)  Does anyone have any experience in this and is this correct as it seems very strange not to be able to map the data over.