I find it very interesting and convenient that when a sibling of the caregiver sends an email, text or letter expressing they do not want to be part of caregiving, it's usually ended with "Do not reply, I will not read it". Well isn't that convenient? Regardless of what the situation is, I think speaking your mind and walking away is simple. But to speak your mind and for once let the other person respond is not. This has happened 3 times to me now, brother has disconnected from family and every so often I get a hateful communication that ends with "Do not reply". I can't wrap my head around it. If there is a problem, be a man and call me or come see me. Don't tell me how much you hate me then run the other way as fast as you can!!! Just saying..
How cowardly!
Guess you have to write that sibling off, unless/until he wants to initiate contact. I am sorry for your loss.