I am not aware of literature that concludes damaged ears are more susceptible to further damage, but I am aware of qualified opinions that state this is the case (here an excerpt from a
2014-article featuring quotes from Bryan Pollard):
"'Significant relapses occur with new noise exposure,' he said. 'We continue to hear from people who follow the bad advice they receive and who go right back out into the world, confused and hurting themselves further.'"
Personally, I consider a damaged ear to be much more fragile.