bitcoind – Is versionbit 28 on testnet something that can be disregarded?

My testnet node is displaying a value in the getblockchaininfo warnings field related to versionbit 28, which I see referenced in various threads going back years.

The angles I’m trying to address are:

• If I’m running the most recent version of core, is it still typical to see unknown rules once in a while? Should this situation be considered an unsupported softfork or something different?

• Where can I find out how to support newly activated rules i.e. what actions to take?

• Is this only some quirk because Bitcoin Classic forked on testnet (see here)?

Here is some info from bitcoin-cli:

–version

    Bitcoin Core RPC client version v25.1
Copyright (C) 2009-2023 The Bitcoin Core developers

Please contribute if you find Bitcoin Core useful. Visit
<https://bitcoincore.org/> for further information about the software.
The source code is available from <https://github.com/bitcoin/bitcoin>.

This is experimental software.
Distributed under the MIT software license, see the accompanying file COPYING
or <https://opensource.org/licenses/MIT>

-getinfo

Chain: test
Blocks: 2537535
Headers: 2537535
Verification progress: 100.0000%
Difficulty: 85961336.19616741

Network: in 1, out 11, total 12
Version: 250100

getblockchaininfo

...
"warnings": "Unknown new rules activated (versionbit 28)"