I think it could be bad form, but I do think that circumstances matter. People who knew the deceased would know that his bio kids were important to him and close with him, if they were. People who knew the deceased would know that his current wife has issues with his bio kids, if she does. The bio kids know they are children of their father, and if their stepmom deliberately slighted them, they have learned something about her. Or maybe they have had nothing to do with their father for 30 years and are not affected by the wording of the obituary at all, while the stepkids have been extremely close with the deceased their entire lives. Any of these scenarios, plus myriad others, could be true and I generally think it is none of my business and pointless to speculate - either I was close enough to the deceased to know what is going on, or I wasn't and it doesn't matter aside from gossipy prurient interest.