In some cases it may be intentional. I am unlikely to open an email from startup X if months ago I reached a negative judgement about startup X.
On the other hand, if the From field only says "John" or "notification", I may open the email even if just for a second.
Also, note the branding value of having your company name in the from field. I receive emails from some sites that I no longer visit. Yet, just seeing their name day in and day out in my email makes me remember their name/brand.
If I was one of those John Schmidts, I would mention the conference. I think this is just a question of providing context in a world of email inundation.
On the other hand, if the From field only says "John" or "notification", I may open the email even if just for a second.
Also, note the branding value of having your company name in the from field. I receive emails from some sites that I no longer visit. Yet, just seeing their name day in and day out in my email makes me remember their name/brand.