It could produce a tsunami but I think the threat is overblown. The island is a tiny speck on the far side of the atlantic and I can’t see it producing a wave of more than a couple of feet on this side of the ocean.
Damaging and expensive yes, but I don’t believe its the catastrophic killer hyped on the disaster shows.
I don’t mean to sound nasty, but it would work like a hydraulic pump, not a pebble in the pond.
If the land slide is significant in size and kinetic energy, it would be horrible for the east coast.