I'm late to the party with this response, but the original post was about how the expectant couple told his mother about the baby by texting a picture of the pregnancy test results. After that, his mother was chilly to the DIL.
One other factor to consider is whether the grandmother-to-be might think a text announcement is a bit impersonal. And that would be on the son as well as on the DIL. Probably more so on the son since that was the way he wanted to tell his mother.
If I were to receive a text that my son and DIL were expecting, I would find it a very impersonal way to share very special news with me. That would deflate my interest in the event.
Our son did call to tell us when he and our DIL were expecting. We had a nice, personal conversation in which we could share our excitement and tell him how much we loved him. His wife was not on that call. Her choice - of course - but she missed an opportunity to share wonderful news with us and create a bond. The kid is a year old now, and she has yet to mention the pregnancy, the baby, or the significant gift we sent. If I had only her to rely on, I would not yet even know I was a grandmother.
So maybe this grandmother's impersonal attitude is a reflection of the impersonal manner in which her son chose to tell her.
We had a death in the family not too long ago - elderly parent. I received many cards, letters and phone calls, and I deeply appreciated each and every one of them. What I did not appreciate, and was actually offended by, were emails from people expressing sympathy for the loss of my parent. How lame. My parent died, and they couldn't bother to pick up the phone and talk to me personally or send a card or hand-written note. That would be too much trouble. I'm sure it is somewhat of a generational thing with me, but to send a sympathy message electronically really rubbed me the wrong way. I am afraid I would have the same reaction to an electronic notification of my son having a child.
I'm sorry for the recent loss of your parent.
I'm afraid there are many people who are not sensitive and/or are at a loss as to how to handle touchy, personal events. It has taken most of my life to figure out that the less said is probably better (especially with a death), especially if I don't know too much about the circumstances; otherwise, it is easy to blunder and say the wrong thing. I have now learned to say "sorry for your loss" or "my condolences for the passing of your ___" instead of mentioning the word "death" because I sense some people don't like hearing that word. Regarding mode of communication, I think the more personal and traditional (like handwriting a note) is better and safer, but I think the reality is many people these days just don't handwrite anything.
A lot of people are clueless/insensitive, and there isn't much one can do about that. They may indeed care but are clumsy about how to show it. I try not to take it personally as a slight or offense. I do hold my close friends and family to a higher standard; I expect them to have some depth in showing love and concern.
I am right now facing writing notes to distant, extended family, who I don't know well, after the sudden death of their mother. I think the best I can do is say I'm sorry and that I'm thinking and praying for them.
In that particular thread, the DIL did as her DH asked, and now the DIL is the one who is getting the chilly reception, not the son. She's actually trying to keep her MIL in the loop, and getting no interest. The son made the mess, and the DIL is paying for it. She's making the effort so many MILs have said they wished they'd get from their DILs.
Personally, I think if anyone takes the time to acknowledge anything significant in my life, I'm not going to criticise their method of doing it. My mother passed away last summer from a sudden illness, she was only 61 and my DB and I had to make the horrible decision to take her off life support. I got support and condolence messages all kinds of way - cards, texts, Facebook messages, e-mails, phone calls, and I was grateful for the outpouring of support we got. Same thing if that's how someone chooses to keep me in the loop. They thought of me enough to keep me in the loop. I was notified at 4am via text that my niece was born. I got immediate notification with a picture, and was just happy for my DB and SIL and excited to meet her.
It might be a generational thing, but it's the reality of the day and it might overlook someone's genuine concern and intentions to dismiss anything electronic.