"Last year they did not add these to magic online because reasons.
What those reasons are we could probably debate about."
I notice that to implement the mechanics of conspiracy would require programming changes to the drafting section.
It is well known that the wotc dev team could not program their way out of a wet paper bag.
If new mechanics of a "fringe" product require changes to the draft section we will not see it online.
For me that is the main reason. I could see other people arguing that we might not have gotten vintage masters without it.
I never got to play a Conspiracy draft just due to my life is in a point where I can't play in person. Then on top of that my favorite store went out of business. Though I did play the heck out of Vintage Masters, and the mono black agro deck I liked depended a little on at least one Conspiracy card. Not sure how that would of changed Vintage Masters or the timeline for Vintage masters.
Another point I could see being made is that it might be more of a social thing and MTGO is about the most anti social thing they could do. Which is said because MTG is social at its heart and origins. So it might defeat the purpose of the draft and also might not get played that much.
There could be other reasons but I don't know of any.