To Oy Vei:
It is true.
I also saw that video recently.
I don’t know why we think that a Godol BaTorah is not allowed to change his mind.
There are numerous instances in the Gemara of Amoraim changing their mind.
On the seder night we read that the heiligge Tanna Rabi Elozor ben Azarya changed his mind.
In our times, Reb Shlomo Zalman and Reb Moshe changed their minds over time on several of their Psakim.
I am very sure that if Reb Chaim Kanievsky would be really meAyin in this Sugya of Tcheiles we might find him wearing Tcheiles himself.