Havoc

The devpost calls those effects “modifiers”.

It is explicitly mentioned in the devpost, that modifiers are NOT the aspect that is different for individuals.
Missions (maps) and mutators (high int, more specialists, hunting grounds, etc.) are what is supposed to be different per player.

I guess you understand, how it could make matchmaking difficult, when one player has “Enclavum Baross with High intensity” and an other player has “Magistrati Oubliette with snipers” instead.
Quickplay would work, but they explicitly said that they do not want to implement it.