Visited on April 3 without charging.
The new chargers are in the same place, reusing the existing green spaces.
The Tesla in my pictures was plugged in (on the wrong side) but the charge was not activated. The app showed that station available. In the live data history I see a car was charging on that connector until 15h, 1h before my visit. I assume it was most likely the same car, and either the car shut down the session when done, or it was remotely terminated.
The "E-Tankstelle" arrow that was still there all this time next to the gate is now valid again and points to actual chargers.
It's not clear who and when you can charge here. It would be a bit of a cheat if you can park here all day for free when every other parking space in Interlaken is paid.