Well, color of that bot tells it doesn’t want to talk here 
But I tried in my forum. AI bot doesn’t answer if mentioned on reply to a post. If it is mentioned in reply to topic (please, you can change right preposition, because I just can’t those small buggers) it answers.
So nothing has changed and expectation is a mentionable bot persona will answer everytime it is mentioned (of course, if an user has rights to do it etc.)
I count this as a bug. But everytime when I’m not sure I use Support.