authority blog/multisite/pro sites

Hi,

We currently have a multi author wordpress site, with thousands of authors contributing content.

My question is if we switch to a multisite, will we loose SEO power from the content our authors are creating.

My understanding is that our multisite would be an authority blog, and then each of our members sites would benefit from all content on the network (our members/authors sites) from an SEO stand point.

Can you please advise, If i have it right?

Thanks in advance