I think you could create an overriding Liquid variable from the index page item and pass it back to the template.
So based on my snippet provided in your other post (Possible to automatically fill SEO page title and SEO canonical? - #2 by Adam.Wilson) you’d want to override the pgOGelsSEOelsName variable for example.
It’s a bit of a complex and confusing setup though 
At the time it seemed to me that If I had added content to a page folder, and then remove it, I would no longer see the index page. It could be that I just wasn’t fastidiously clearing the page and leaving behind some spaces. In any case I can’t replicate now.
I think this is a case of empty vs null values. So your previous code might have been doing something like:
{% if this['description'] != '' %}
rather than:
{% if this['description'] != null %}