Earlier quoted context omitted.
Personally, I'd hope the system would absolutely tell them "tough shit". There's got to be a line where the safety net gives out, because someone is too expensive to help. That's where family and charity hopefully take over. At the same time, I think your instinct is right, and it's something I've never heard mentioned before. It's almost inevitably that there'll then be the "food security" fund, and the "housing gua…
You'll find there are two voices for BI, the liberal and the liberatian. The liberal would prefer to keep universal healthcare and food programs and put cash on top, making the total distribution to the poor larger. The liberatian would prefer to simply move the complex paternalistic safety net into a simpler cash payment which doesn't disincentivize work while not increasing it's size. As an aside, if you pay attent…
Actually, I think the two main groups are both libertarian, though there's a left-libertarian and a right-libertarian viewpoint, with the libertarians that aren't strongly left- or right- splitting between them.
I personally prefer keeping the existing means-tested programs but counting UBI as income when considering eligibility, such that with growing UBI [0] you eventually reach the point where the income floor is above the eligibility level for the means-tested programs, allowing them to be discontinued.
[0] I also prefer basically tying UBI to a tax stream that should grow with economic growth, with mechanisms to provide reserves so that you don't have UBI drop with cyclical recessions.