The businesswoman stepped down from the board in December 2008 and in April this year sold her 15.9% shareholding to the American entrepreneur Stan Kroenke, who now owns a majority stake.
Writing on Twitter, Bracewell-Smith said: "I agree that current board should all go. They are passé. Have nothing more to give to the club at all. In time we will need a more dynamic pro-active, younger board, and a good directional leadership."
In a post that has since been removed, she reportedly added: "[They] couldn't handle a woman with power on the board. Felt insecure. Male chauvinism."
She went on to claim that former Gunners vice-chairman David Dein was "the root cause of all the troubles" at the Emirates.
However, in a retraction posted today she conceded: "I stand corrected. Dein loves the club and although sometimes personalities fall out, his contribution at Arsenal has been immense."