Are bipolar logic familes like ECL/CML used currently for radiation hardened computing devices?
The killer for CMOS built on bulk silicon is the current that radiation produces in junctions that are supposed to be providing isolation. One way around this is to build CMOS on top of an insulating substrate, such as sapphire.

The lowly RCA 1802 "COSMAC" processor was used in a number early satellite projects precisely because it was available in a SoS (silicon-on-sapphire) process that was inherently radiation-resistant.