I am simply asking if the WT asks parents to kick their minors out of the house when they are disfellowshipped.
No, they don't, never did. However, I have seen many kids leave before adulthood, or before getting any higher education. Now, indeed some parents have thrown their kids out as soon as they turned 18, and yet, I believe that the topic is more complexe than some may think.
Ex-JW kids around 16 often want to draw their own path, away from an over bearing cult that comes with its mental abuse. Mental abuse that is channelled through their loving parents and all their friends. And so, understanding that they can take small jobs and move away, they do, even if this is against their parent's wishes! They are thinking: "Well, even if I have it hard, it won't be as hard as getting that look from my parents that says I'll die at Armageddon soon".
And then, there's the kid who's behavior is abusive towards his family for several years. Fighting, disrespecting, cursing, lying, yelling, stealing, breaking things, never participating in any house work. Such behavior can have its toll on the parents and at some point, when the kid is old enough to work, the best think for everyone is to send the kid out, often with the assistance of social workers. This type of thing happens with JWs and non JWs alike.
In the end, all I'm saying is that its not possible to make a broad general statement about this.