Until they exercise it I suspect we can't truly know. They have demonstrated that have reliable drone manufacturing and ballistic capabilities. Whether those include submersibles or munitions that can strike submerged targets is unclear.

In terms of raw capabilities and ability to actually damage these cables as an entity. Yes they have them today, they don't need special naval craft for such an endeavor, you can drag a hook behind any vessel large enough for the conditions and damage the cables repeatedly. This has been happening in other parts of the globe for some time, with Russia using cargo ships, I believe. Other parties could try and prevent this, possibly with some success but it would either involve sinking those vessels at a distance (hope they're right about what those vessels are doing), or putting your own assets in danger of missile or drone strikes.