The four values you mention are good ones trisher and part of being British.
I don't see any reason why British values should not continue.
1 Democracy is still in evidence and no reason why it should not continue as usual
2. Welcoming. (Britain has always taken in those who need help from the Hugenots to the Kindertransport and should continue to do so.)
The two you mention were many years ago and, interestingly, two examples of refugees from oppression in Europe.
I hope, too, that we will continue to treat refugees with care and compassion and not just leave them to fend for themselves as happens in some countries.
3 Tolerance I wonder if social media has a lot to do with the perception that we are more intolerant now? I think that, with some exceptions, most people we meet in RL are in fact as tolerant as ever - not all were and not all are now but I think the majority are.
4 Support and care for the weakest should continue. As for charitable causes, the British public have always proved to be very generous with their money and their time.