Why such a significant change? Well, for one thing, it should help reduce the chat load on specific nodes during fleet operations, and it also serves to help split up the game’s functionality into more manageable chunks for the development team. It also gives the game’s customer service team easier access to chat logs, so that should be fun, too. You shouldn’t notice any changes in-game after the chat changeover, but players are encouraged to report any bugs that managed to slip through as always.
EVE Online players who will be heartbroken over the loss of the game’s voice chat will really just be riding the forefront of the game’s chat changes. Significant backend changes to the game’s chat functionality are coming with the March update, and the short version is that chat in general is getting spun out to a separate platform on a different infrastructure.
Source: Official Site