It’s not only about laws, but also frequency regulations and plug compatibility and voltage regulations
UK Government has already stated out that they want to uniformise with the US, so that products are compatible between US and UK.
As for the warranty, UK has always been against two years of warranty, they voted against it, but they lost. However you can be sure this is something that will change after brexit happens in the comming year.
Don’t believe that all laws will be adopted, it might be adopted in a first phase to have a smooth transitioning so that markets are not to nervous, but when the markets have calmed down, they will start pruning in the laws.