You have it completely backwards, rather than ask what drawbacks there are to China intervening militarily in Syria, instead you should be asking why China should be directly involved at all.
Yes, Uighur terrorist armies getting a safe haven in Syria is far from ideal, but it’s not like they don’t already have safe havens elsewhere already. What, is China going to have its own war on terror and chase them throughout the Middle East and beyond? And even then what is the actual point? Anti-China jihadists are the symptoms, not the source. China is currently focused on dealing directly with the source, America. Without CIA money, training, weapons and safe havens, these guys are zero threat to China.
Besides, the true reason the Syrian civil war remained unresolved was not because ‘Assad sucks’ or ‘Russians lazy’ or similar western troupes. The true reason these terrorists have not been eradicated was because America did not allow it. They killed hundreds of Wagner troops in Syria directly to make that point. So unless and until you are in a position to directly fight America in Syria and win, it’s pointless getting involved. Because you can spend all the money and lives you want to get into a winning position only to get stopped from winning by the Americans.
