I can see it breaking off from the land based ice but since it's already floating, it's not going to displace any more water than it already is. Thus, the oceans aren't going to rise.
Kinda like filling a glass with ice then filling it up to the rim with water. As the ice melts, there is no rise in water level.
The damage will be caused by the sudden collapse although it would be short lived. You would get tsunami waves radiating out from the place where the ice sheet collapsed. It would float back up again but for a minute or two it would make quite a mess.
Glaciers – large sheets of ice and snow – exist on land all year long. They are found in the mountains of every continent except Australia. Greenland and Antarctica contain giant ice sheets that are also considered glaciers. As temperatures rise, glaciers melt faster than they accumulate new snow. As these ice sheets and glaciers melt, the water eventually runs into the ocean, causing sea level to rise.
Icebergs and frozen seawater also melt in warm temperatures but are not significant contributors to sea level rise. This is because they are already in the water. The volume of water they displace as ice is about the same as the volume of water they add to the ocean when they melt. As a result, sea level does not rise when sea ice melts.
While density differences between salt water and freshwater result in a difference between the volume of salty sea water being displaced by sea ice and the freshwater that would result from the melting of that sea ice, it is minimal.But for the record (and I hope for a warmer climate were I am)
NOAA’s 2022 Sea Level Rise Technical Report suggests that sea levels could rise as much as seven feet by 2050 unless more is done to curb future emissions