It can be done, but the way to do it really depends on your game. For example, if you want the camera to slide over to some other NPC, this can be done through the event system described in the second tutorial video.
If you want to change the name of the NPC that you’re displaying, this can be done in multiple ways. Again, event system can achieve that. Or you can add speaker field to every node. Or it can be a reference to an NPC and retrieve name, portrait, NPC position for camera from there. There are many ways to go about it and they all depend on the frequency of multiple speaker occurences and on your game behavior when the speaker changes.
TL;DR: If you don’t know C++, I suggest the event system (explained in the second tutorial video), because it’s entirely in blueprints and easy to use.