You do want to make sure you're buying the bitcoin well in advance of any troubles or divorce though. If you have $100,000 in your bank account and suddenly it's gone and you claim you don't have any other assets, it's not going to work during divorce proceedings.
My Father in law is an attorney. They excel at finding that kind of stuff. You could only move currency in small amounts over a period of time.
What happens if you move it all over to bitcoin, keep it, but say you lost it all at an online bitcoin casino? Never getting married but that would be my go to play.
Then you run the risk of gambling charges and perjury if they can prove otherwise.
All this is true, but have you been in court lately? Most judges are literally like Dinosaurs...especially ones in Family Court. They will have a hard time wrapping their head around BTC, and at the end of the day, they won't be able to understand what is going on. They will just get a fair market value and slap the husband with a judgement.
If your soon to be ex-wife has enough money and is disgruntled enough to hire a forensic accountant, it may be time to waive the white flag.