Like many of folks here, I have to toy with disavow tool every now and then to purge my site from bad links.
I've heard someone assumed that not only do you have to specify new domains/links in a disavow file you want to get rid of, but also those you disavowed earlier.
The party who said that believed that there is one and only one disavow file stored in Google, so whenever you upload a new one, the old one gets replaced along with the domains specified in it.
Hence, you have to include all the links/domains you wish to disavow along with those disavowed earlier.
There is no backup of the theory from Google as far as I know, so my question is simple - is it true and is there any proof of it?