The main reasons for wanting to disavow links are a) to combat negative SEO to disavow spammy links that a competitor might have placed to harm your site; or b) to disavow spam / paid links purchased by some black hat SEOs (a particular problem for me at the moment having just taken over a naive client who has been suckered by a black hat SEO company!)
Remember we are talking here about a verified webmaster disavowing almost certain spam links, for example 2,500 links from one domain embedded in blog comments. I doubt we're talking single links from odd sites we don't know.
So I can't see this working in any other way than a webmaster spotting unknown dodgy links such as x,000 from domain xxx and disavowing them, and Google then ignoring all links from that domain. No positive impact, no negative impact. Just ignored. Why make life more complicated than that?