Why? They try to keep all information secret, especially the one that make USSR looks bad. For example, they denied existence of Level 6 nuclear accident for 30 years [0].

If the nuclear accident which had 10,000 people evacuated was suppressed and denied for 30 years, why would you trust them to publish any negative information about military computer?

[0] https://en.wikipedia.org/wiki/Mayak#Kyshtym_disaster