Wow. This thing is huge. Looks like it might be more thorough than the Wiki timeline.
Checking on the part of the timeline I'm currently playing in (2073), I notice something odd:
2073 - On July 18, the Great Dragon Ghostwalker performs a ritual that closes
Dunkelzahn's Rift in Washington, FDC. Over six hundred civilians are killed,
nearly two thousand more injured, and almost three hundred fifty are missing,
believed pulled into the rift (SINless victims are not included in the official
body count).(Shadowrun Wikia)
According to Artifacts Unbound, he used the 4 artifacts from DotA, which includes the Sextant of the Worlds, to close that rift.
2073 - In late July, shadowrunners steal the Sextant of the Worlds from Aztechnology's Pyramid Arcane Supplies in Bogotá and transport it through the rainforest to Caracas.(Shadowrun Wikia)
2073 - On July 29, Cardinal Eduardo Ortega-Nunez is assassinated during a press conference announcing that the Catholic Church has recaptured the Sextant of the Worlds; Picador and Black Mamba are among the teams hired by other parties to recover the Sextant. (Shadowrun Wikia)
So in a very short time, Ghostwalker used it, it somehow ended up in Aztechnology's hands again, the Catholic Church knew about it, arranged to steal it and was ready to announce that they now had it.