First off, a single priest murdered and a bunch of hostages is nothing compared to the crime in any Euro hellhole muzzie nation.
Second, the unfortunate realty of Islamic countries is always low level challengers rising up trying to take command for themselves, and, going to war against their fellow Muslims. Look at the history of any Islamic empire, and there is, every 5-20 years or so, some uprising of Muslims trying to kill their own leaders saying they now have the mandate from Allah to lead. It's fundamentally in the religion of Islam, that Islam must be always expanding and conquering, so there always Muslim opportunists lurking in the shadow ready to kill their own leaders and seize power claiming they will lead their people to victory.
You may think since Christians were targeted, and taken hostage, this is about Muslims attacking Christians, which is what these rebels want the public to think. In reality, this is a Muslim vs. Muslim war, and Christians are being used as provocation.
What it really comes down to is this:
Notice, this governor's son is part of the "militant attack," which can only mean there is a power struggle within the Islamic world inside of Russia. Who they really want to kill is this guy:
Kadyrov is currently the most powerful Muslim in Russia, and part of his power relies on allying with Christians like Putin to maintain control.
That is why Kadyrov's direct challengers are targeting Christians, try and provoke a response from Christians, and unseat Kadyrov from power by having Christians inside of Russia over-react and attack Muslims in anger. The challengers to Kadyrov know that if they can spark a Muslim-Christian Civil War, then Kadyrov will lose his support from Christian Putin and be vulnerable to attack.
That's what is really going on, and this is part and parcel of any Islamic culture. There are ALWAYS challengers to the throne inside of the Muslim world. This is why the Christians in Dagestan weren't simply murdered, but taken hostage, so they can obviously be used as leverage against Kadyrov.
This isn't actually a problem of Orthodox Russians - it's a problem for Kadyrov, because it's really a direct challenge to his power. Now we will see what kind of a ruthless response he will have to maintain his leadership role over Islamic Russia. Historical Muslim responses involve parading the heads of the challengers on a stick through towns to scare off any would-be challengers.