It's important to remember that many recent employment law cases ruled on employment law. There's no requirement for HMRC to follow these findings for tax purposes but you expect they'll be reviewing their position.
Along similar lines, there have been some recent HMRC 'IR35 status' tribunal cases where (usually) one-person limited companies have had mixed success as to whether they are an employee of their clients.
The Chancellor's humour today peppered around some dry, but important, statistics won't prevent today's headline being all about the self employed Class 4 national insurance increase from 9% to 10% in April 2018 and 11% from April 2019.
Voting works! UK small businesses, pensioners and parents vote whereas large international companies can't. With an eye on attracting these votes, as long as you're a saver, the Chancellor aims to deliver a package to attract you!