Yes, they had these plans from the get-go so launching the necessary hardware is not surprising. The question was whether anything like that went live

Once it does go live, anyone could see the lower ping between two users of this network. If they say it got enabled, that wouldn't be hard to independently verify

What demonstrates ISL use is service availability in the middle of oceans, far from any ground station.

https://www.starlinkflights.com/how-to-check-starlink-flight:

"Unlike older geostationary satellite systems that had coverage gaps and high latency over remote oceans, Starlink's low-earth orbit constellation covers the entire globe. Qatar Airways, United Airlines, Alaska Airlines, and airBaltic all offer uninterrupted Starlink on long-haul international routes."

Its already live, Starlink works in the Arctic far outside the line of sight of any base station.