Are these going to be your own videos or do you want the plug-in to just randomly scrape YouTube based on keywords and it would automatically generate code for your WordPress posts.
This is an interesting project but I don't think it is an interesting project.
I think the main value of doing this is to cut down on bounce rate.
Generally speaking the when people see a video that is tightly related to your blog post, they would spend time watching the video and this can mean this can make or break the bounce rate average of that page, and as you probably already know since the rank brain update Google is paying close attention to bounce rate.
According to Google if it detects that people stay on that page and they don't bounce out, this means that the searcher actually got what they're looking for.
This in turn can increase your rankings.
That's why some services offer this manual linking service.
I would think that this can work against you because if it's obvious that the video has nothing to do with the content, people will bounce out.
In fact it might even accelerate the speed at which they bounce out because they only need to look at the thumbnail and if they see that it's completely unrelated to the title as well as the other text on the page they're gonna bounce out.
So, you might want to tighten your selection of the tool that you're using to automate this so that there is a stronger correlation or connection between the existing content of the page and the YouTube videos that will appear with it.
