I'll take a stab at this.

Everything on the forum tagged under GiveDirectly touches on basic income. See their recent post Early findings from the world’s largest UBI study for a research report and Ending extreme poverty through cash transfers should be a central EA cause for a spirited debate on the merits of basic income. So I would not say that "no one is talking about UBI." It ebbs and flows.

As to whether that income should be universal, I think most EAs would argue against, for reasons that strike me as pretty straightforward applications of our collective commitment to impartial welfarism, maximizing utility, and cosmopolitanism. In other words,  because we are always triaging, we should be focusing our efforts on the causes where a marginal dollar goes furthest, and that concern usually militates against universality. 

Looking at the total discussion of UBI and UBI-related subjects on the forum, I think it's a good proportion: not too much, not too little.