Because سوق does not "look" feminine (that is, it lacks the ة ending), many people mistakenly use masculine adjectives with it.
Do a Google search for حرب with a masculine adjective and I'm sure you'll find similar results. Nevertheless, everybody always says only الحرب العالمية الأولى - but maybe that's like a "fixed expression."
Also, nouns like عروس ("bride") would never be used with masculine adjectives because they are obviously feminine.
I don't know but I am skeptical. Why would a grammar book give incorrect but popular examples without warning the readers?
For the record, I checked the suuq entry in Hans Wehr again: It says that the gender is mostly female (no idea what mostly means ) and it gives a couple of examples for both masculine (mushtarak) and feminine (7urra) collocations.
Now I'm stumped. "As-suuqu 'l-7urra" sounds great to me (in fact, the masculine wouldn't sound as good), but so does "As-suuqu 'l-mushtarak" (the feminine here would not sound as good).
Before you shared these details, I blithely assumed that it was technically feminine but was sometimes used with the masculine due to the lack of a feminine ending (by the way, in colloquial Palestinian Arabic we almost always use masculine adjectives with it - as with "7arb" - with the exception of "is-suu2 il-7urra," which I thought was a "fixed expression" like "il-7arb il-3aalamiyye 'l-2uula). However, the fact that both uses seem to be supported as correct sheds new light on things.
Could it be that this particular noun allows both genders, depending on the adjective that follows? Sounds quite ridiculous but you never know.
What I know is : suuq and tariiq are both feminine, but we use them as masculine in colloquial
Bur in Fus7a suuq only comes in feminine -as much as I know- :
As for tariiq, I can't come with an example, but will look in some grammar books and get back to you