I'm not sure I would describe the rise of Wahabism or the Al-Saud as a "rebellion." The Nejd from which the first Saudi state emerged was not under Ottoman control and they had no need to overthrow any local rulers in order to expand their state. That the leaders of the first Saudi state were executed at the conclusion of the war shows that their actions in taking power were perhaps viewed as criminal or that they were illegitimate, but I can't recall ever seeing them described as rebels. Had they remained confined to the Nejd and not tried to seize Ottoman territory in the Hejaz or to sack Ottoman cities like Karbala I don't think anyone would have bothered them.

That being said, and to get to your question, while I haven't read the works of Muhammad ibn abd al-Wahab directly, I have never come across any suggestion that Christian sectarianism would have been a question he would have had any interest in whatsoever. On the contrary, it seems to me that his entire message was based on devoting oneself entirely to a proper study and understanding of Islam with no outside influences whatsoever. In that sense I'm also not entirely sure what the relevance of it would have been whether or not he was aware that such a thing had taken place.