i am sorry about your fil.
i will say that even though your h received this horrible news, is not license to "confide" in the ow....regardless of the situation. that really has nothing to do with the ow...it has to do with your h. if the ow contacts him, then he should let you know, and together you both decide if you would go nc or not. nc is always best.
i wouldnt "ease up", shut down, drown out, or waver in your expectations of what is a healthy boundary in your m....or healing based on this horrible news.
i feel like i am being harsh writing this...but i just dont want your feelings to be compromised during this painful time. you know what i mean?