Hideo Kojima has now explained why Ocelot is voiced by Troy Baker in Metal Gear Solid V: The Phantom Pain.
Ocelot appears in all of the main entry Metal Gear Solid games, but is always voiced by different people. In Metal Gear Solid V: The Phantom Pain, he is voiced by none other than Troy Baker.
Hideo Kojima tweeted the following to explain:
Ocelot appeared in MGS1, 2. 3 &4 and reappear in MGSV after the break in PW, and becoming regular character in MGS series. Every time we use different voice actors as his characteristics, age, and position differs depending on the story.
Metal Gear Solid V: The Phantom Pain is set in the year of 1984. Ocelot wasn’t the young rookie we saw him in Metal Gear Solid 3. He’s also not the old man we saw him in all of the other games. Ocelot is middle-aged now, so this is why Troy Baker was chosen to voice him.
This is a similar explanation as to why Kiefer Sutherland is voicing Big Boss in Metal Gear Solid V: The Phantom Pain. Kojima dropped David Hayter for Sutherland as he wanted Big Boss to feel like a different character to Solid Snake.