I guess it's always possible to use something like this for money laundering.
I.e.: (1) Send 1BTC to address whose private key is publicly known.
(2) Sweep the funds a few minutes later (depending on the amount of plausible deniability vs. risk you're willing to take).
(3) Claim you mistakenly sent the funds and that they're gone, since it's an address whose private key is known.
Alternatively, generate private key with relative weak (but not publicly known) string before executing your idea. After some time you could make an account on social media/forum and claim you found another weak Brainwallets which already emptied.
P.S. This is informative post, i'm not taking any responsibility if you weaken your privacy or lose your money

.
I guess it's always possible to use something like this for money laundering.
I.e.: (1) Send 1BTC to address whose private key is publicly known.
(2) See how your BTC was collected by someone else's bot.
(3) Cry because you are a loser

The outcome could be different if there's pool also run such bot which automatically submit the transaction to constructed block or many nodes enable
-mempoolfullrbf on Bitcoin Core 24.0[1].
[1]
https://github.com/bitcoin/bitcoin/pull/25353