For example, if you have TPM backed FDE, TPM-backed encryption for your wallet, and the screen locked on login, you can still get a pretty high level of security.
Sure, but they specifically asked for it to unlock on autologin. Meaning no password to be entered. If you lock the screen right away, you still need to put in a password, so that is not what they want.
Is there any way to automatically unlock the Kwallet with Autologin (sddm) in Plasma 6?
Yes there is. https://wiki.archlinux.org/title/KDE_Wallet#Unlock_KDE_Wallet_automatically_on_login
These are already my settings, but from Plasma 6 I am asked for my password every time I log in.
No. You might aswell not use a wallet in that case, since nothing is protecting your passwords.
That really depends on what backs it up.
For example, if you have TPM backed FDE, TPM-backed encryption for your wallet, and the screen locked on login, you can still get a pretty high level of security.
Sure, but they specifically asked for it to unlock on autologin. Meaning no password to be entered. If you lock the screen right away, you still need to put in a password, so that is not what they want.
They asked it to unlock their wallet on autologin, which is separate from whether the screen is locked.