Definition of brave new world:

a future world, situation, or development

also :

a recent development or recently changed situation

Those definitions are rather ambiguous and 'developments/situations/changed situations' could go either way, positive or negative, good or bad. Merriam Webster has been known to change definitions. Wonder if these have been changed at all.

I’d say Q isn’t referring to the dystopian novel.

Since Q wrote “beautiful”

So beautiful future is what I Believe Q said

This is the meaning I've always hoped they meant.