That's UK though right tikha?
There are, currently and historically, anonymous donor gametes available in many countries, some countries insist upon it, and there are many differences between countries, even within the EU, so there are now adults who were donor conceived who are now speaking out about their experiences, as noted in the link you shared.
The woman, Millie, who I shared her you tube video of earlier, is now 26/27.
thembeforeus.com/millie-fontana/
No one can predict how a child may feel as an adult, being donor conceived, including the child themselves. Many will be fine about it, others won't be.
Another woman who has spoken about this OP, (though her circumstances are a bit different as she was born as a result of a traditional surrogacy arrangement (so was related to her surrogate mother as it was her egg) is Jessica Kerns:
nypost.com/2014/06/16/children-of-surrogacy-campaign-to-outlaw-the-practice/
I imagine there is lot for you to explore OP, from the questions of related siblings from the same eggs to the health of the donor and the lack of research.
www.weareeggdonors.com/blog/tober-interview