Imagine the FLY chart and all the big blue routes depicted as a way to circulate around class Bravo airspace without disturbing ATC and the regular flow of trafic. ATC’s expect you fly these routes without clearance. But for VFR in this overcrowded airspace, it’s always a good idea to take Flight Following. NB: in FLY charts there are also VFR transition routes which required clearances.
Another good example of FLY chart is for Vegas area where VFR corridors connect GA airfields around the international airport
In this case, it looks like you’ll be under radar vector and I suggest you follow ATC instructions by the book 