Disney Canon: Absolutely not
The exhaust port flaw was included by Galen Erso, one of the designers of the Death Star, as a means of deliberately sabotaging the Empire:
“My colleagues,” Galen said, “many of them, have fooled themselves into
thinking they are creating something so terrible and powerful it will
never be used. But they’re wrong. No weapon has ever been left on the
shelf. And the day is coming soon when it will be unleashed.”
His head turned from the recorder as if what he said next, more than
anything, he feared to say aloud.
“I’ve placed a flaw deep within the system. A scar so small and
powerful, they’ll never find it.”
Rogue One: A Star Wars Story
As for the nature of the flaw he included:
And as he envisioned the cataclysmic energies building within the vast
station, he saw it—a detail he had overlooked and forgotten, some
trivial adjustment of Galen’s: a single exhaust port leading from a
narrow trench down and down, down kilometers of blackness, past
conduits and hatches and radiation plating, down and down—
—and into
the main reactor.
The primary weapon of the Death Star battle station fired.
Orson Krennic, advanced weapons research director and father of the
Death Star, died alone on Scarif, screaming in fury at Galen Erso, at
Jyn Erso, at Wilhuff Tarkin, and at all the galaxy.
Rogue One: A Star Wars Story
This of course contradicts the various explanations proposed by the previous Legends canon.