Am I just a dinosaur in this social media whirlpool? Have normal manners (?) and protocol gone straight into the toilet? I'm baffled. A little background ...

My mom and dad divorced almost 50 years ago and my dad remarried (I attended the wedding). They soon had two boys (twins) and we're not super close (one lives in California and one in Washington state), but we stay in touch. We spent quite a bit of time together while they were kids (when I lived in California) and when the family moved to Florida, they stayed at our house for a month or two while they were house hunting. My step-mom and I talk maybe once/mo. and I know the rest of her family and we talk occasionally.

I talked to my step-mom around the end of July and she said she had been diagnosed with stage 4 pancreatic cancer. She had an appointment on 8/1 to discuss treatment options, so around the 3rd or 4th I called her to get an update, but the phone went straight to voicemail. This continued for 4-5 days, so I wondered if maybe she'd been admitted. I called both my half-brothers and was told she's declined chemo and has gone into hospice, but was pretty incoherent 90% of the time. I asked them to keep me informed.

Well, last night I happened to be perusing my FB page and noticed BOTH of them had posts on their FB pages that my step-mom passed away yesterday! I called everyone on OUR side of the family and not one of them knew anything about it! I still have not received a call, text or even an email notifying me.

Is this what the social media world has turned into? The boys are in their early 40's, both college educated and fairly successful. I'm SURE ... kind'a ... that I'll hear from at least one of them soon ... but I'm not sure I should hold my breath. I'm sure they're busy with arrangements, etc, so maybe they think the "announcement" on FB is all that's required, I dunno. Comments? Opinions? Is this the new norm?