No, there won't be a PC beta, since they've already had a PC client in the japanese version, despite all the bugs that probably won't get fixed between the Xbox and PC version, since they require testing on both platforms. (IE: the character customization lag won't be fixed on PC. Since it would require testing on PC, which they aren't planning on doing.)
For those unaware, Xbox One uses a special version of Windows 10, which Microsoft had hoped to help bring more games to the PC as well through the whole unification system they had planned between Xbox and PC.