Ask an Immigration Solicitor. Get an Answer ASAP.
Good morning, as you have pre settled status you are able to stay outside the U.K. for up to 2 years. If you plan to bring your family they would need to start living in the U.K. by 31 December 2020 and apply for pre settled by June 2021.
Currently with Brexit there has been no update so as the current rules stand they can apply for a family permit until there is a further update.
As mentioned above as of now they would be but going forward no new legislation has been put forward for Brexit.
I advise waiting for the updates on Brexit if they are planning to come in June however it would be advisable to come to the U.K. by December as we do not know what will happen with Eea nationals.
It was a pleasure assisting you today.