As he was for vaccinations it's more likely part of a group that wants to end boosters rather than leave the decision to the medics. Perhaps he sees that as where his future is. There has always been back ground rumbles within the party about all aspects of covid handling.
You take the man seriously?

There is no accounting for taste.
The current narrative is more interesting. NHS and rail. One problem on the NHS is privatizing overspill and those that could ldischarged. Rail appears to be about inadequate profit levels. The same is cropping up in the general area of public transport by other means.