If you are CV you have not been required to shield so far, and it strikes me as pretty unlikely they will ask more people to shield in future as it's such an awful thing to ask of people.
Even now, the CEV are meant to be shunning going inside into shops, meeting lots of people etc. And yes, if you look closely at the deshielding letter, although it's intended to be permanent in terms of the fuller isolation, there are hints that advice could change in the future. And of course around 50,000 people are continuing to shield on medical advice. But most of thebshiekding support services have been dismantled.
The effectiveness of the jab varies depending on which co-morbidity has cause a person to be classed as CEV (shield) or CV (vaccine group 6). For some, they can expect similar to the general population. For the immune compromised CEV, it's as low as 13% (blood cancer patients, source BMJ, but later research is not quite so pessimistic)
It does I'm afraid mean that the chances of the vaccine not working well, or not working at all, are higher if they are telling you that with your co-morbidity it is 60%. And the nature and severity of the co-morbidity might cancel out and age/sex/weight advantages you have.
Speak to your doctor at your next appointment about what might be the most sensible level of precaution that is reasonable for you.