The NTSB, etc., have been trying to get AOA indicators available to airline pilots for DECADES. But so far the regulators and industry remain opposed to the idea.
No, they are not opposed to the availability of AoA indicators, otherwise boeing couldn't offer it as a customer option on the 737 (and probably other types). But apparently they do not see the need for them or they would be a requirement.
AoA information of all three AoA vanes is actually available on the bus, however only via the CDU and in numeric values, not something one would do in a dynamic situation like that. And i guess displaying the difference between where the aircraft is going versus where it is pointing, although readily available via a simple "bird on", is beyond the reduced mental capability of the pilots during an event like that.