https://en.wikipedia.org/wiki/Smoke_detector mentions none of this.
You're right, it's bogus.
I was told that decades ago. But a little research (in the online patent databases) shows that there were ionization smoke detectors for decades before that (back in the tube era, even, when beta emitters were easily available to the common man). NASA says their only involvement with smoke detector design was (in collaboration with Honeywell) coming up with a variable-sensitivity design to stop annoying false alarms in Skylab.
Sorry to have repeated a myth. B-b
If you are smart enough to know that you're not smart enough to be an Engineer, then you're in Business.