No, it's not.

This is just a proxy statement, meaning it includes all proposals shareholders will be asked to vote on at Twitter's next annual meeting (on May 22nd). Everyone can submit shareholder proposals who owns at least 2000$ of stock [1]. This does not mean that anything will actually happen: The board of Twitter recommends voting AGAINST the proposal and I doubt large institutional investors will vote against the board on this, so the measure will most likely fail.

And even in the quite unlikely case the measure would be approved, it is only asking for a "report" on what selling Twitter to its users would mean. It does not argue for such a sale to actually take place.

[1]: http://theshareholderactivist.com/shareholder-activism-spotl...