A recent set of posts made me curious about this feature that GNOME had introduced.
So what the unwanted feature basically does is that it opens any launched window minimised and gives a notification "Application is ready". This only happens if you launch an app and immediately change focus by clicking or scrolling somewhere else before the app can open.
To avoid this from happening, I have found a nice extension which works very nicely and is well maintained unlike many others which also provide the same function.
You will first need to install the gnome shell integration in you favourite browser to make things easier (if you haven't done that already). Just go to extensions.gnome.org and click on the link at the top:
and then install NoAnnoyance V2 extension from here.
Problem solved...You can thank me now.