Yes, i t is only very limited tax changes in area - eg new Welsh stamp duty is coming out and Scotland and England now have different stamp duties.
One reason HMRC must delay their plans to make the self employed use new ditigal software and keep accoutns in new ways, file information 4 times a year etc is because of the need to change VAT following Brexit. It is going to be far too complicated to do both around the same time or at least I hope HMRC realises that.
the new EU data protection law comes in in 2018 before Brexit. On that issue I doubt the Government will then repeal it in 2019 for example but we shall see. It is deregulatory in a way as instead of businesses like mine paying every year to be registered for holding personal data that requirement will go.