It’s nothing to do with OE parts for a specific make of bike. The Dutch company just sell universal accessories. If the U.K. owners of Dutch style bikes can’t get a pannier or a lamp in the U.K., then they will just have to go without. Tell me what you want for your Dutch bike and I’ll have a look for an alternative for you.So you gone from licensing to screw them who cares? That means you are saying screw you to all the UK owners, enthusiasts etc who bought their products, thus making their investments worthless or taking a big hit.
You really didn't think it through other than Brexit lets stick it to them foreigners.