As with any discussion, and especially one pertaining to halachah, clear definition of terms is required. This discussion adds the need for accurate and consistent translation of terms as well.
There is NO issur giluach on ones head. Peyos (edges/corners of ones head) may not be rounded even with a machine/trimmer which cuts in the manner of a scissors.
There IS an issur giluach on ones face (this week’s sedra, I believe). The Gemora learns out that this prohibition is only when done derech hashchasah (not a scissors).
The issue of shavers has always been (the Chofetz Chaim discusses this in his Likutei HALACHOS on Maseches Makos) are these machines acting as scissors or as razors.
How and when the definition of “beged ishah” changes requires a posek.
Inyonei kabbolah and midos chasidus cannot be ignored or dismissed as we learned last week Kedoshim Tihiyu is a mitzvah min haTorah.
Rav Chaim, as I posted earlier, does NOT prohibit shaving. He does paskin, I believe, that at least some of our “shavers” are razors al pi halachah and therefore prohibited min haTorah. He may also be saying we should be makpid on how we “dress (i.e. like traditional Jews who always had beards). He is certainly entitled to that opinion, and I would value it as it is certainly coming from having learned a few more blatt Gemora and from chazering Shulchan Aruch a few more times than we have.
No, he is NOT paskenning for the entire world, but we CAN’T either. Even for ourselves, it is advisable to ask for oneself.