Sony Group's Ethereum Layer 2 Sonium May Launch Testnet on 28th

It appears that a testnet for Soneium, Sony Group's Ethereum Layer 2 chain, will be launched.
On the 25th, Sonium published a post via OfficialX (formerly Twitter) suggesting the launch of the testnet on the 28th.
Sonium is a joint venture between Sony and the Asta Foundation, a spin-off Web3 company called Startale Labs.
Sony Block Solutions Labs, a joint venture of Sony Block Solutions Labs,
It was developed using Mystic Rollup technology. Because it is built on Optimistic Rollup, it can be linked to other networks via the Super Chain.
In the early stages of the launch, the company plans to operate a testnet in cooperation with Aster, a Japanese public blockchain company.