I'm very doubtful for a public test. The closest we will get is a demo a month or two before release.
As said before, the only way to test is to physically visit Larian. This is how testing has been done since 2001 prior to the release of Divinity: Sword of Lies (a.k.a. Divine Divinity).
Astral Projection won't work either as there are some left over ghosts from the first game that will beat you up.
