"China has threatened there will be "consequences" for countries that show their support for Liu by attending the event."
- Sounds like a ill advised attempt to threaten to me.
On the other hand China could have used quiet back channel diplomacy to persuade India not to attend. Openly threatening almost certainly ensured India's participation.
China must give support to some big ticket item that India aspires to really expect consistent Indian cooperation. China has tried to block every major initiative that India has undertaken. If China were to openly support India permanent membership to UNGC I believe it can expect significant...
The reason if at all India decides not to participate must be based on principles. It must not do so just to satisfy China. It should not bow to Chinese pressure.