Can you include html in word replacements?
There's a WIP PR (work-in-progress code change) that if I remember right while reviewing it made it mostly work, but I do think html is iffy right now.

https://github.com/civicrm/civicrm-core/pull/15836#issuecomment-553702913

You could do it with an extension that just inserts some jquery that appends your text to the existing &lt;div&gt;. https://docs.civicrm.org/dev/en/latest/framework/region/