Will there be a normal long-term maintenance testnet?

[flyq]

Although the sdk tool is great, developers need a more realistic environment to test products, especially when need to interact with NNS canisters, or when demonstrating projects to others.

Such as

How to setup a local development environment / local testnet?

Some applications may rely on the system-level canisters, such as the ledger canister, cycles minting canister, internet identity, etc. I’m trying to write a deploy script that can help deploy these canisters to setup a local development environment automatically for developers. I only managed to successfully deploy the ledger canister and the internet identity, are there any instructions or documents on how to deploy these canisters? aaaaa-aa nns/ic-management …

So is there any official plan to run a testnet?