Hello You're right, in saying information isn't readily available, but we can figure out from what information we get:
We figured out that they would phone us because expats over 80 have been phoned the day before, and locals were phoned the day before too.
We figured that we needed to be registered in the Spanish health system for them to have our details and our phone numbers too. And friends from the UK had gotten health system cards.
The expat over 80 was from the UK, and had to go through the Social Security offices in Almeria to register, and to get their health cards. I presume because being from the UK the health agreements they would have whilst in the EU still hold even after Brexit...
We are irish, and haven't worked in Spain, as such haven't been seen as entitled to free healthcare here in Spain, as yet. The document we have to show that we are registered with the the local healthcare centre is a temporary one. Not a card. We too have private healthcare insurance that we are very pleased with.
So, if you are in some way know to them, registered as living there or in the care of their particular health centre, and if they have your phone number, I presume that's how they would get in touch perhaps?
Our friend from the UK wanted to know if we asked when vaccination would happen for our group, but we didn't ask. I get the feeling is that rollout is happening as quickly as possibe, and when one group gets the first shot, they move on to the next.
On communicating, asking questions, and getting help:
I agree it can be a bit of a mystery.... and watching someone's jaw drop when they feel under pressure and don't know what I'm trying to ask about can be funny at times...
We had misunderstood the oft cited manana attitude here after ordering windows during a glass shortage, and the family firm obliged in making them available just before Christmas by opening on a Saturday, but we sauntered in hours late....
Differences in culture and attitudes can seem insurmpuntable....
But overall, I've lived in France from time to time and have lived here for about 15 years more or less, and everywhere, to my surprise even over the phone when trying to ask someone for technical help, and not always having the right words to say, a smile really helps!!!! If I could have measured the decrease in stress on the secretary's face in our local Ayuntamiento, or the increased response time experienced when looking for a person to fix our phone in France, I'd offer these in evidence!
In short, everyone means well, and as to when it's going to happen, everyone's doing their best.
We've also noticed that medical personnel don't tend to speak in English, possibly in case of mistakes being made. This is a legitimate issue: I misunderstood when being told that I was being brought to surgery, thinking it was for an exam, as the consultant was going to see me there... it was for an op, and I'd eaten... they delayed surgery for a few days!!! Good luck!