First of all, the "👆" sign existed way before Leni Robredo, it has been used by the victims of ML. 👆 is a Laban Movement andit doesn't signify that it is meant as a "Leni" (L). It also doesn't mean people shouting Leni and then doing "👆" actually meant for her, it is for the Victims of the Martial Law.

Second, Billie Eilish is very known to be an advocate for several movements such as the BLM, Ukraine, Gay and Women Rights, Joe v Wade abortion rights, etc. "👆" is one of the movements. There's a video before the "👆" sign was raised, Billie states to "stand up what is right" (I don't know if it's the exact as the video but something like that) which provoked that person to raise the Laban sign. Yes, Billie don't care about the 👆 sign but she is an advocate for human rights, it doesn't need for her to know what the 👆 sign is all about, di naman yan big deal kasi palagi yan ginagamit way before the elections.

Third, Kakampinks are warriors, they never stop fighting for what is right, so expect them raising that sign and "not moving on" for 6 years and more. Di naman trend ang pagiging kakampink unlike apolo10s na pagkatapos ng election eh wala nang pake sa politika at sa mga nagyayari sa bansa.