I don't think they are moving by choice. They have effectively been kicked out by the Mayor as they want to develop that area.
I was working in an office that overlooked the Bernabeu last week and you could just make out the crane on the horizon and the building site of the new stadium. Losing your stadium is one thing, but shifting it to out of town, I think you lose your soul. But as demonstrated so many times, this support dusts itself off and gets on with what they do best, supporting their club.
Last night all the Atleti fans stayed behind to congratulate their players. When Real came out again, all their fans had gone home. Joke of a club and terrible support.