I really think having done some googling that these provisions don't substantially change the situation.
It looks as if the reason for bringing it in is to do with other changes to residence and contact legislation when parents separate. Previously you could get a residence order specifying who child was to live with.
Then anyone could apply for a contact order in relation to any child, under which the court orders amount type and frequency of contact. BUT that person first had to get leave of the court to make the application.
So although contact orders are mainly used in separated families, it has always been open to a birth parent to seek leave to apply for a contact order in relation to their child. However I would imagine that the threshold for getting leave has always been very high. From that article it looks as if there has been the odd case over indirect contact, being decided either way.
We were told at adoption stage that the contact agreement was made on a goodwill basis, but that if we didn't keep to it there was the possibility that the birth parents could go back to court and seek a contact order. For that reason I haven't signed up to contact agreements for either of my children without feeling I could stick to them in good faith.
Now I understand that residence and contact orders are being abolished and replaced with 'child arrangements orders' that combine the two. Obviously not appropriate for an adoption situation. So it looks to me as if the new legislation is seeking to keep open the possibility of birth parents applying for contact, but make it specific to adoption. So in fact the legislation could be better for all concerned.
The question I imagine is whether badging this as adoption specific will raise awareness of the option, and whether birth parents will be badly advised as to their chances of making a successful application, leading to more distressing court cases on all sides.
I also wonder whether this could lead to prospective adopters thinking more deeply, and having more nuanced conversations with SWs, about what sort of direct or indirect contact is really right for the child they're adopting, and signing up to an agreement they are genuinely committed to keeping. It seems to me that if a contact arrangement had been properly considered, decided in child's best interests and kept to in good faith, a birth parent would be unlikely to obtain leave to apply for a different arrangement.
Mammoth post which I hope makes some sense and provides some reassurance all round!