Just to clarify the web reputation on talosintelligence.com is not the same as SDR.
SDR is not reflected on talosintelligence.com. As it currently needs the entire email header to look up an SDR score.
I have not seen reports of O365 hosted domains specifically being marked poor, however if there are false positives I would recommend opening a TAC case to get that investigated through Talos. We might get additional details that way.