I've never seen that bend on any of my #7's. I have some new ones out of the package right now.
I can put a steel straight edge along the straight (non-diverging) route rails, and they look dead straight to me.
Funny this topic about the "bent" #5's came up. I have only 3 #5's in my whole plan, to fan out into a roundhouse,
and ironically, that slight bend helped! It's like a very slight "Y".
(I'm not endorsing this defect. I'm just saying I got lucky in that it helped out in my case!)