Is it appropriate to suggest to someone just diagnosed with cancer to get their affairs in order (specifically a will, medical and financial power of attorney and an advanced directive aka living will)? And if yes, how aggressively would you approach the situation?

Details: Cancer patient is your FIL, 61 years old, is the sole provider for your MIL 62 and 30 year old BIL (he doesn't work, no medical reason, that's a different can of worms) sole owner of the house (15 years left of mortgage, not in the best condition), vehicles (5 years left on loan), and bank accounts. Job doesn't offer disability or paid sick leave. MIL doesn't work, or drive, or even have an ID of any kind, she's basically a ghost. MIL would ultimately live at your home if something happened to FIL and BIL would essentially be homeless.

Medical Factors: Lung Cancer. Inoperable. High stroke risk due to previous heart issues. Had a quadruple bypass 12 years ago and has type 2 diabetes.

Family has had about 6 weeks to wrap their brain around likely cancer diagnosis while tests were ongoing. Denial is a strong family trait but cancer was confirmed this past week.