Ah... Yeah, I'd think 2000 years would be ample time for the rough coasts to erode to something more closely resembling the kinds of coast we're used to seeing and turning a lot of those peninsulas into archipelagos.

I suppose if you're talking about a lot of rocky canyons, that time scale could work. I'm not really sure how long it would take for the ocean to break up something like the Colorado River basin, which is the sort of canyon I have in my mind: File:Lake Powell - Arizona.JPG - Wikipedia, the free encyclopedia