Why would anyone want to do this?
Two reasons :
1. More users, more clicks, more engagement
The more buttons you have leading to your bot, more likely your users are to use your bot. Simple math.
2. Keep users on your site
An issue with native links as they were before was that the user was redirected away from your site. This new method, allows you to keep native links but since the bot opens in the widget instead of in a new tab. So when users finish interacting with your bot, they can continue navigating on your site.
How can you use this method?