The government promised to do this in a previous election manifesto by 2020-21, so in effect it you are getting it one year earlier than planned. It has already been confirmed that the tax free allowances, which has traditionally been increased on an annual basis, will be frozen next year, so at this stage (and this may all change dependent on Brexit) it is a "one year giveaway"
For those who complete a personal tax return, and for any reason miss the deadline and receive the automatic £100 fine, this system is changing to a "points based system". Miss one deadline and you won't be fined automatically ( as with the current system), but receive a "penalty"point. However, points make prizes for HMRC and, for serial offenders, the points ( and financial penalties) will mount up quickly.