Reaching for any ridiculous explanation, no matter how contrived, rather than just observing the obvious patterns in the animators’ habits that have been consistent since the show’s inception.
Hmm… would the magic disturbances during the first 1000-year imprisonment (NMM says hi) have given Discord some sort of rock-spasms that weakened his prison?
If not, then why is there still a royal garden left after his escape?
It doesn’t have to be identical to be re-used. All they have to do is shift a few elements and change the timing, as opposed to remaking it from scratch.