Important thing to take from that.
Now the question remains, is crowdsourced forums/message boards 'illegitimate tax advisors'.
For the meat aspect, tax avoidance structuring which is legal, will remain legal, and advisors advising such are not breaking the law.
Tax avoidance structuring which is illegal, will have advisors criminally charged.
Comes back to...
I have a idea, a business and i think in a few years i will do well, so i set up a structure so as to reduce any potential future taxes, by paying a premium to structure my business ahead of the potential point i might︀ have to pay tax = LEGAL.
I have just made a lot of money and︁ now am trying to create a structure to reduce the tax owed = ILLEGAL