I'd say 50/50 with an increasing number of semi-animist Oromos converting to Pentecostalism, Abiye Ahmed etc. Apart from Arsis, AQ, Jimma assimilated Oromos etc., many Western Oromos do not have a tribal loyalty to Islam unlike Somalis. A lot are culturally Muslim, relatively poor and are ripe for evangelisation as can be seen in the following conversion.
It does not help that Oromo nationalism goes against Islam as it puts Oromo unity above Islam due to the religious heterogeneity of Oromos hence why you will see Muslim Oromos cavorting with Pentes, Orthodox Oromos when celebrating pagan Oromo cultural symbols.
Moreover, Ethiopia is a secular country politically dominated by Christianity thus there is nothing stopping American funded evangelisation and the continued growth of Pentecostalism among Oromos. Popular Oromo Pente prosperity gospel pastors are swimming in lacaag and have huge audiences who contributed financially to their religious hustle. They got a booming gospel music scene attracting more Cawaan Oromos to their flashy version of religion.
Ain't got a problem with some of their beauties being Pente as the Curly haired one ain't bad looking, wouldn't mind having her type as a concubine in the Xalal sense.