Hellow this is tobey, i would like to comment.

Why you developer or GM CM never add ramadhan event? All the game community respect the agenda and even valve big company add it and add 90% sale. Why u guys in 4 years never add it? Even though u guys add other religion agenda such as easter egg valentine and etc. Plz comment it developer

Good questions, as Muslim community for Ramadan(Saum) Event.
1) Surely, they(Developer) need to require Permissions from Muslim community either We(Muslim) would either be agree to allow or Forbid.
2) Muslim has highly very sensative(conflict) from any related Pagans Event(such as April Fool/Halloween/Christ-mass). Example, A Player would tend to Characterize their own appearances wearing Pagans outfit even Titled "Lord of Pagan" while celebrateing Ramadan in this game, would be Probihited for Muslim.
Prohibited, due to Players might doing mockery and Amusement.
|Al-Qur'an - Ali(Family) of Imran - Verse 57|
3) Surely, it might be complicated to add so.

Just take a look what IS did in Russia. Al hamdullah with your Ramadam event