According to the confidential elders’ manual “Shepherding the Flock of God”, that sentiment would technically constitute “apostasy”.
If you express doubts about the vaccine is that doubting the GB are who they say they are? If so then many many JWs including many elders are doubting the GB then they are all apostates?
Even expressing doubts that someone wishes they didn’t take so many of these vaccines as they have been bad for your health, that is doubting the GB direction? But many are indeed doing this