I don't know if I would call this a "ban" if the average person is allowed to own 500 grams.
At the current price of gold, that is over half a million dollars in gold per person.
This isn't going to effect the average person, only the VERY wealthy.
While some of these very wealthy might buy some amount of Bitcoin, I doubt it would be their first choice for investment.
Probably they will have some offshore accounts, invest in foreign currency and bonds, etc.
Something like this isn't going to create half a billion new Bitcoin users, not even half a million.