As to the Navy making the event public, it appears to be part and parcel of the drip, drip, drip disclosure of "something" by the Pentagon dovetailing with its report to the Senate Select Committee on Intel due in a few months.
Seeing if you can get up close and personal to the US Navy without being detected would be a legitimate test of technology for foreign militaries, American black projects, etc. Obviously we can rule that out in this case as they were practically screaming,”We’re here!” Whether it was a foreign nation with the intent to harass or us with the intent of being spotted and recorded for propaganda purposes is still unclear. (You know that I’m deeply suspicious of this roll out of info.)