French Lighting youtuber running North American 13W preheat PL adapters on 120V 50Hz supplies:

https://youtu.be/E8Njw6sztlU?si=AKyyDMp8BrnlW2-j

https://youtu.be/lCOqKiWExCY?si=CS4lVjHkqbMOIKzO

https://youtu.be/HzSUx6UTuPA?si=5v-mUeaj4JHNB7k9

Check out what the youtuber said in regards to running 60Hz magnetic ballasts on 50Hz supplies:

“Do not be worried. During the test, the adapter was plugged into an inverter that supplied the adapter with adequate voltage. As for the electrical frequency, the passage of 50Hz on a ballast designed for 60Hz does not lead to overheating (temperature controlled over a period of one hour of use). nevertheless, conversely, yes there would have been damage to the equipment.”


“Indeed it is possible. But in this way too. American adapters support European 50Hz very well. As long as it’s not a clock or motor, it has no consequences.”

Does anyone think that this information is dangerously misleading?

Not as much misleading, as it is simply ignorant.

Although it's also very much possible that he is right, and it is truly not overheating. After all, if it's designed for 40 degree texas summers and you're now running it in 20 degree Paris, it might be still safe to operate purely because it's designed for higher ambient temperatures.
It's always a risk. I know my wilcox-gay record lathe motor draws too much current at 50hz to be able to operate it for more than 1 record side at a time.