This is just my opinion, but I don't believe the production of a game should be changed in any way for modders, who do not even make up the majority of Bethesda's fans.
Modders and people who
use mods make up a huge percentage of fans. I would venture to say that they actually are the majority.
Either way, I think my solution is fair for everyone. They could use my emotional-expression ("sighs" and body language) as a filler for the voice work on the first disc. This way, all the data from that first disc is completely together, and you don't have to keep switching out discs for any reason.
And there's more room for content on that single disc.
On additional discs, the voice acting can be included as plugins. The spare discs mean that the only limit to the voice acting is budget and sheer amount of dialogue. These discs would be installed onto the console's hard drive.
Those who prefer voice acting still have it,
more of it,
and more game content. Those who prefer the filler voice effects (to make mods better integrated) can simply choose not to use them. Everybody wins!