The idea that US citizens need to scrub their phones before entering the US is just a hysterical media narrative related to the drama around a certain middle east conflict right now (which I shall not mention because it will further devolve into a flame war).
I can tell you with certainty the amount of border agents who have a strong opinion about this certain middle eastern conflict is exceedingly small.
This seems to imply that public discussions about cleaning phones wasn't a meaningfully common occurrence before now.
But it's been a spontaneous topic for as long as devices have been at risk from border agencies - since at least 2017.
> has begun
ICE has been arresting, detaining and exiling US citizens for at least 10 years:
https://migrantinsider.com/p/ice-has-deported-at-least-70-us...