I’m going to continue on the pragmatic approach:
If you two are divorced, then the financial and legal-rights separation should be clear. What is yours and what is hers is part of the D process and no judge would have signed the decree if there was any uncertainty there.
What you two might have thought or what might have been implied is not relevant. If she THOUGHT, you would remarry and then she would get her rights to your pension or whatever doesn’t matter. What matters is what was signed and accepted by the court.
I hope and want to believe you will survive your illness. I hope you respond well to treatment and battle this and win.
But once again: pragmatic…
Go through ALL documents that are relevant to the situation.
Make a will: Have it legally done by an attorney where you clearly state where your money goes, who should manage the estate and so on.
Designate an executor: Do you have a brother, uncle, aunt, niece… anyone that you know is a cold, logical and ethical person? Attorneys are often used, but they tend to charge by the hour and gnaw at the estate. Someone that you have had the difficult talk to about your will, what you want and so on can pay dividends.
Check your insurance policies: Any life-insurance? Who gets the pay-out?
End of life: With your doctor and possibly a priest or moral guide decide how far and long you want to go. At what point are you OK with having the switches flipped.
Who gets to decide, be with you and know: While married then by law that’s your wife. Divorced and she will by default be denied entry into the ER or post-op or to see your files or take part in any decision if you aren’t capable. Decide who gets that role now and prepare them.
Talk to your bank about how to access your accounts if you aren’t able or have passed away. I know of a widow who had to borrow money from family because she couldn’t access her dead husbands accounts for over 4 months after his passing. The bank was sympathetic, but “correctly” pointed out that the man had never marked the box granting her access.
I’m probably skipping several issues here… It might sound macabre and maybe defeatist. But in reality, MOST of the above are things ANY and EVERY person should consider. You might be facing a potentially fatal disease, but we all face the risk of getting run over by a car or tripping and breaking our neck. Cover these bases NOW while you have time, health and the mental capabilities and it will give you peace moving on.