Maybe I read Antigone too many times in high school and college but unless the deceased specified that he wanted this in his will it comes off as grotesque, like burying (or not burying) someone not in accordance with their last wishes.
The story is a bit sparse but as best I can tell it's not like he exactly had a certificate of deposit at the sperm bank. If he did then you could rationalize this on the grounds that he'd already conceded that he wanted kids but wasn't sure of the timeline.