Being blocked by someone using family sharing

Blocking a Contact applies to communication with a person, it will block messages or phone calls. But it does not apply to family sharing. Block calls and messages from certain people – Apple Support (UK)

A family member who is blocking you may not be able to receive your invitation to join the family group and share the subscriptions and accept it. Add a family member to your subscriptions from Apple - Apple Support

I have never heard of "blocking" in the context of Family Sharing. Perhaps you could provide more detail? Who is the Organizer of the family?

Perhaps the contents of these article may help you:

Add a family member to your subscriptions from Apple - Apple Support

How to share purchases with your family - Apple Support

Again I do not understand what you mean by "block". I know of no such thing possible in Family Sharing unless you are the Organizer and you turn off purchase sharing (and even then it is not called "block").

I would think they could still get access to the subscription. The blocking to which you refer is the telephone number and is not in any way related to Family Sharing. In fact you wouldn't even need to have a telephone number or service in order to use Family Sharing.

A family member who is blocking you may not be able to receive your invitation to join the family group and share the subscriptions and accept it.

I got the impression this person was already part of the family.

OP: "I was wondering if that affects their ability to continue to be in my family sharing or not."