He claims that not all bc1 wallets will work with the Lightning Network.
Only P2WPKH wallets will work, i.e. multi-sig.
2FA and other P2WSHs will not work.
Using P2WPKH does not imply you are using multi-sig, your 'i.e.' is wrong.
Funds spent to bc1 addresses can either be P2WPKH or P2WSH. The length would determine which of these it is.
I think Electrum will warn not allow you to enable Lightning if you have the wrong wallet type. So I don't know if it really make sense to warn about this up-front, users will find out.