In the case of Fallout, I believe there is an actual list of names that they supported, which were all individually recorded by the VA, it can't adapt to whatever random name you throw at it. Most TTS systems can't pronounce things correctly without an extensive library full of rules for specific words, either.
But, in time, it may get there. Deepfake tech will surely assist in that part of things, so one day we'll be able to toggle all of our MC's internal monologues to sound like James Earl Jones or Morgan Freeman. Or if you're a real sadist, Richard Attenborough.