I agree that minimum wage raises are the wrong conversation, and that they’re relatively easy “wins” for liberal legislators, since there’s no need to raise taxes. But going straight to basic income is a stretch. Many economists prefer the Earned Income Tax Credit (EITC) to minimum wage increases (though some consider it a complement), and as a cash grant EITC is much more closely aligned to the UBI vision than minimum wage. There’s also precedent for local versions, as many states have their own EITC (California just expanded theirs last year), and it enjoys bipartisan political support. Long-term and with enough UBI support, EITC could expand to include more workers, and ultimately even the unemployed to become UBI.
So to answer your headline question, no I don’t believe UBI supporters should support raising the minimum wage, they should try to shift the discussion to expanding EITC as a stepping stone to UBI.