If I had a nickel for every time this topic has been raised on this forum, I'd buy Microsoft from Bill Gates.
No, this is not an official policy of the JWs.
That said, as others have pointed out here, the WT makes frequent reference to the "spiritually weak" and also provides frequent warnings about "even within the congregations, there are those who may not be wholesome association" or some such tommyrot.
And of course, there are many uber-self-righteous JWs who are only too happy to put 2 & 2 together & reason that "they must be talking about inactives". And who then proceed to virtually shun them.
JWs are pretty much wack-a-doodle.