Well Mike, that doesn't explain it right there.
First off, I HIGHLY doubt that every other park in the world will have giga coaster. Within the next 10 years, I expect to see possibly 8 or 9 counting the two already existing ones.
Anyway, back on topic, if they wanted to build higher than the 275 feet the FAA restricted them to, they would either need to get special FAA clearance like Raven_Rider said, or they would simply just be denied the rights to build it.
If it was a certain length drop they were looking to achive, they could simply do as Buffalo Bills did in Las Vegas with Desparado, and build an underground tunnel.
Hope that answers your question.
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"Shut up brain, or I'll stab you with a Q-tip!"
~From the brilliant mind of Homer J. Simpson.