So they likely have to wait out the green card process abroad unless they secure a dual-intent visa like an H-1B.
There's also 75 countries that the US has shut down consular processing for so those people may be locked out getting a green card entirely.
You could go the fiancé visa route and stay in status while waiting for the green card.
I think what this policy is trying to avoid is the blanket “you can stay while processing even if you’re not in the country legally”