It can be said that this has been a long time in coming, where Google has begun to look into the very real possibility of integrating Google Voice into Hangouts when it comes to the Android operating system. However, there seems to be a very good reason behind the fact that Google has introduced this change on the quiet, as users have already started to step forward and share on a fair number of bugs as well as potential hiccups concerning this passing of the baton from Voice to Hangouts.
Apparently, some users have reported that messages which have been received by Voice too, are slowly but surely appearing on Hangouts without issue, while replies aren’t exactly the most stable of options at this point in time since they do not get sent out prim and proper, which means that making the jump would be pointless right now.
Apart from that, if you were to make this switch, it will result in your Google Voice extension in Chrome to cease working, which translates to your inability to check as well as respond to texts on your computer. Last but not least, it is impossible to select the number you would use whenever you respond to a text, as you will remain locked in to whichever number that it hailed from. Hopefully all of these growing pains will be sorted out sooner rather than later!