If you follow the links, it goes back to the announcement blog entry. It does *not* say that a Pi4A has been ruled out. What it does say is that they haven't identified a less-than-$35 way to do it yet.
It is my *personal* opinion that there may never be a Pi4A, and--for similar reasons--there may never be a CM4. I think both will be worked on, but there are significant challenges that may not make either one economically viable. I think a Pi5A and CM5 are more likely, since by the time those would be feasible the RPT will be a lot more comfortable working though the issues around the radical hardware changes that have come with the Pi4B.
What I would like to see is a revision to the Pi2B to give a "Pi2Bv1.4" as basically an underclocked (say, roughly 1GHz) Pi4B without WiFi and--perhaps--only one HDMI connector. I doubt there would be enough market demand to support such a beast, but if such a thing hit the market, I'd get at least 6 of them and probably more like 10.