Oh hells to the yes! Speculation! Rumor! Yarn spinning! Tall tale telling!... epic epicness at it's best!
Given that the series has already established that the Veil has very "weak" spots (usually incurred when a terrible or powerful magical event takes place) since Dragon Age: Origins (Remember Warden's Keep: Sophia's speech!), it is very possible that the events of the last decade (in the Calendar of Thedas, it has been a total of 10 full years leading up to these events starting for 9:30 Dragon to 9:40 dragon) have simply weakened the veil to such a degree, that it simply does not protect one realm from the other when applying even a minimal amount of effort from either realm to tear it asunder. Given the host of major magical events such as:
- The considerable amount of magic that Flemeth must have expended just to maintain the secret of their hut in the Wilds (which, of coarse, actually leads way back farther than just 9:30 Dragon)
- The Mass possessions of the Circle of Magi at Lake Calenhad
- (potentially if actually done) The killing of the high dragon at the Urn of Sacred Ashes temple
- The killing of the Old god Urthemiel ending the 5th blight
- (potentially) meddling incurred by the Architect
- The attempted mass possession of Templars in Kirkwall
- Anders magical destruction of the Chantry in Kirkwall
- (potentially) the amount of magic Orsino used to become the abomination.
(note: and certainly this is far from an all inclusive list! I am sure more epic dragon age geeklords could include other potentially powerful events I missed!)
So, just from this speculator point of view, clearly the veil has been, figuratively, nearly ripped to shreds. So you take a powerful magic event (similar to Anders destructive spell) at such a magical nexus point like the Temple of the Urn and it points to subjecting the veil to the business end of a serious ass whoppin'! Thus, creating all the little rifts as minimal force from either our realm or the Fade would be needed to punch through!
Morrigan did say "Change is coming to world".. She never said it was progress!