Sounds like Nigerian officials putting out platitudes to appease the west.Looks like the western puppets are pushing for war in Niger. France is officially backing the invasion. Obviously they are demanding the return of their colonial resources.
However, apparently the Nigerian senators are wary of backing the president and military push for war against Niger.
I doubt we see a Niger-Nigerian war. Nigeria is an African superpower, but they already have their hands full dealing with their own insurgency. As @Africablack already succinctly described, Nigeria is a very divided country with multiple very different ethnicities. The north of Nigeria is probably sympathetic to the new Niger government, while the south couldn't care less. Zero interest for war.
They could get one of the smaller African countries to launch an invasion, supported by NATO. If a war does break out, expect a European refugee crisis that eclipses Syria and Ukraine.
About the Mali "coup" (of course only pro-western movements get to be peaceful revolutions). Russia and China working together to combat western colonialism in Africa is much more effective compared to the Cold War when they were constantly at each other's throats.