Sherby
Sorry this is a bit long, but if you are able and willing to help, why not get some clarification from the staff? I think you might have misinterpreted the policy as nothing like this has happened at my daughter's preschool.
I think "insured for children under 2" means that they can't be responsible for them, ie you can't leave your baby there and go home, but you are allowed to bring them as long as you take full responsibility. That's how it works at my daughter's preschool. After all how could they get any helpers if that was the case? Most mums are either working or have younger children, don't they?
Being "inclusive" I think means that they don't exclude mums with new babies and working parents but I don't think Ofsted can make it compulsory. However if they are a bit short of help they might have used this change in policy to be a bit more assertive in asking people to help. But I don't think they could seriously force you to help but not allow you to bring your baby. Not everyone has friends and relatives that they can call on to babysit or can afford to pay for childcare out of your own pocket!
I have a 7 month old as well as a 3.75 year old and the baby is always welcome and the children always enjoy meeting her. Now she is older she enjoys it too!
I found that it was actually easier to help when the baby was younger as she would sleep most of the time and I could just park the pushchair in the kitchen. When she woke up I would feed her on a comfy chair and the children would come and look. I didn't really have to do anything because the baby was such a novelty for them! Now she is more alert and won't sleep, but she enjoys watching and smiling at the children, and goes home a bit overtired. But when she starts crawling it will be even more difficult to keep her out of danger!
Although I felt some trepidation at helping, I actually enjoyed it enormously. Helping gave me an opprotunity to meet my older daugher's friends (who she talks about endlessly) and see how different she was away from home!
All the best, it won't be that bad! It actually is quite fun and you won't have to do it very often.