One only has to ask if the coastlines of Europe disappeared at the time when the “Vikings” settled in Greenland? They didn’t.
The NASA calculations seem to impute every drop of “melt” as landing in the sea, and none in the air, none becoming rain clouds, none becoming rain over land that fills landlocked lakes, and underground aquifers; all just melted into the seas. They are not scientists.
The sea ice melting would lower not raise sea level, fill a glass with crushed ice fill with water to a bubble, when ice melts does it over flow or recede?