I have no basis for assuming that U. of Arizona’s maps are more accurate, though that app seems to be built on standard GIS datasets instead of Google Maps and the NASA survey. Does it mean its more accurate because it’s been built by geoscience guys? Perhaps. Perhaps not. For my part of the world its scenarios track pretty closely with yours — and that’s as far as my analysis can go.

Firstly ‘Flood Maps’ covers 1-14m of sea level rise, not 1-7m.

Secondly, I don’t think the University of Arizona maps are much more reliable than mine. They don’t take tides or coastal defenses into account either: Here are their techincal details.