I asked him if there is a time limit on how long the Dark One can hold the souls he grabs.
He said that he is not sure and might have to consult the notes but he thinks that there is a time limit.
I think that should put an end to the theories that the Dark One has been holding any souls for hundreds or even thousands of years.
If you are viewing this on github.io, you can see that this site is open source. Please do not try to improve this page. It is auto-generated by a python script. If you have suggestions for improvements, please start a discussion on the github repo or the Discord.