This basically means players from several new regions will now be able to join the good folk from North America and partake in Alpha testing of Blizzard’s upcoming MOBA.
Next phase of the Heroes of the Storm Technical Alpha is beginning “soon”. Here’s a quote from the original Battle.net post:
These upcoming phases of testing will allow opted-in players from North America, Europe, Latin America, South East Asia, Australia, and New Zealand to have a chance at being selected to take part in the Heroes of the Storm Technical Alpha. During this upcoming phase of testing, we will continue to use the English client for all applicable regions until our fully localized clients are ready.