I'm not sure those two are related. A 'thought vector' seems far more advanced than emulating emotion in voice no? Though you raise a good point about text itself not carrying any weight behind it. Solution here could be to also be able to tag words as 'emotional' or 'angry' in a visual editor, which the NN uses as hints when synthesizing.
Many games approximate a reasonable thought vector already. For example, Mount & Blade: Warband is a fantastic but relatively dated game (2010) which creates a world of hundreds of characters, each of which dynamically alter their relationship with the player along a single-axis based upon complex events. When pressed for information on subjects such as who within an alliance should be allocated newly conquered lands, they will make a decision and explain themselves by virtue of their relationship with others and the player. Whilst simplistic, it's actually extremely immersive already... and that was 2010. This year a 2016 remake Mount & Blade: Bannerlord is due for release... looking forward to wasting hundreds of hours more examining improvements!
