Wagner Group captures headquarters of the Southern Military District and the building of the Ministry of Internal Affairs in Rostov, the headquarters of Russia's base of operations for War in Ukraine
Everyone tries to control the narrative, this is completely normal. Anti-terrorist operation, peacekeeping mission, special military operation, march for X. I don't remember someone who just said "yep, we are invading X".
In this case both Prigozhin and Putin (or the establishment) are trying to control the narrative to gather support from "patriots". Saying you are making a coup sounds antigonizing, while saying you are marching for justice, because it's the government who has betrayed the people does not.