Wonder if the Spaceship will allow Musk to send up a serious satellite-based backhaul option. Sounds like there'll be some money to be made there, perhaps sooner than anticipated...
AAE-1 alone has a capacity of 40Tbps (the article says terabytes - that's wrong; EIG is <4Tbps, TGN Atlantic is ~5Tbps), and so assuming the numbers I found are right, you'd need to be able to aggregate bandwidth across 500 Starlink sats for uplink, 500 more for the downlinks, and whatever number you need for laser links between the endpoints.
There are at lot of submarine cables[1], though, so while I don't doubt that there will be people looking for contracts to use Starlink for some degree of extra redundancy and worst-case offload, the primary redundancy for these cables will be other cables, along other routes at least until Starlink gets a couple of generations further.
Laws of physics still apply even to space based connectivity technologies.
https://www.space.com/spacex-starshield-space-force-contract