This is a bunch of self-serving BS promoted by motorcyclist who think they are entitled to go to the front of the line.  

Some motorcycles accelerate more quickly - many - particularly e-bikes - are a hazard because they drive so slowly.

It does not free up space for drivers - they now have to wait longer for those motorbikes who used to be behind them to accelerate and get out of the way.

As for safety, they will be a whole lot safer if they are not darting through lanes of traffic to get to the front of the line.  

Obey the rules of the road like everyone else.