This isn't part of mainstream scenarios, but there are credible studies projecting such a sealevel rise, see e.g this study: https://science.sciencemag.org/content/349/6244/aaa4019

Here's an article on it: https://www.salon.com/2015/07/10/this_is_what_its_going_to_l...

Some predictions are even more extreme: https://phys.org/news/2015-09-fossil-fuel-meter-sea.html

It's probably not the most likely outcome, but it's also definitely not "fear mongering bs", it's part of what science is discussing as possibilities.