Nobody has been talking about UBI except in the same sense that people talk about warp drives, i.e. as a nice-to-have-someday bit of speculative fiction. Everyone is aware that if UBI were actually proposed in the political sphere it would be killed immediately, by most of the some oligarchs who dishonestly talk about it now.
But when consumers disappear and the wealth is threatened, won’t it simply be the only solution to keep the show going for the oligarchs? It may well be inevitable.
High income consumers are a steadily increasing percentage of consumer spending, and the bottom 60% of consumers are something like 20% of all spend. One outcome is just that the trend continues and high income consumers spend more which offsets decreases in low income consumers.