>>57902040
No, I think Giratina-O would've proven to be too much for OU overtime. It's one of the strongest Pokemon in Ubers in Gen 6 and 7. It just isn't obviously broken like most other Ubers. It's more of a broken strong Gluemon.

Smogon isn't against dropping Ubers to OU. Darkrai, Deoxys, and Genesect have been tested multiple times. Kyurem-B and Zamazenta dropped to OU as well. Giratina isn't beyond the pail, it's just sleeper OP.