Inbound marketing-lead nurturing-gated content

I have a question about when to gate content. We have been doing inbound marketing campaigns for lead generation. We create whitepapers on relevant industry related topics that our potential customer base would find valuable, we gate the content and then do a LinkedIn campaign and often partner with an industry magazine to use their email service to generate new leads not currently in our database. We then send out 3 nurturing emails to those that download the paper.

My question is what to do with our existing leads database when launching new campaigns. There is an internal debate on this with a differing opinion from various team members. For me, the purpose of creating the whitepaper is new lead generation so I would still send an email to existing leads (some are actually customers in our leads database...don't ask, the list is mess) but I want to send them a link to an un-gated version. I only want to gate it for new leads. It seems odd to me that we would force people to put in their information to access the whitepaper when we already have their info on file.

Any thoughts on this? Do you think that if we ask people we have on file to fill in their information again to see the paper that it may have value for us, like showing an increased interest so we could categorize them as having greater potential?

Thanks for your input!