My speculation level is at full but the SR-71 program was the gold standard and I think it's good to tap those responsible for it. They were doing some incredible stuff 60 short years ago and dismissing it as "old" is folly.
The SR-71 was uncontested in the 70'ies, but it wouldn't be today. Today it would be vulnerable. Missiles reach higher and fly faster. There are missiles that are designed to intercept ICBM's, which come in faster than a Mach-3 SR-71.
Radar detection, tracking and firing has also become much more effective in the last 60 years.