They are due to the EU roadworthiness act (2014/45) coming into force.
The draft documents are inspection manuals for annual tests and inspections of light vans, medium vans, heavy trucks, and passenger service vehicles (buses and coaches). They outline acceptable reasons for failure, application of requirements, testing procedures and standards.
A quick read of the documents suggests numerous relatively minor changes, including a new portrait-orientation layout for HGVs and PSVs. For example, for these two vehicles, the minimum criteria for pressure buildup has increased. The current standard is for two fully-assisted brake applications after the warning device indicates minimum effective working condition. That level of performance has been reclassified as a dangerous defect; less than four applications is now a major defect.
The three draft documents are linked below.
Light commercial vehicles
HGVs
PSVs