No. Holocaust > 4 days > Irvine joins group > 20 years (although dimension travel will probably be used to cover most of this time period) > Time Matrix location discovered, but Ken'atra gets it first.
Your character could not have gone back in time to do anything that remotely concerns the Revenant....and refer to what I said earlier. Besides, currently the Holocaust thread IS the actual universe. It hasn't been changed yet.
Thus, if your explanation is right, Irvine is trying to stop the Holocaust from being stopped before the actions of stopping of it exist in the time stream.
Also, the way you described the 'time streaming device' shows it has nothing to do at all with the Time Matrix, which is a silvery, indestuctible ball. It is not at all based on known SW technology - remember the Cantina-verse is the Star Wars universe with some elements of fantasy added in. I would compare the Time Matrix to the One Ring from LotR more than to something like a lightsaber.
(In fact, the size-changing capabilites of the Time Matrix was directly inspired by the Ring's properties)
As for your last comment on Jedi, it's only been four days since the Holocaust - people, including Force adepts (like for example, Alys) are still trying to figure things out, you'd think.
If you really want this storyline, you need to make it fit with what's currently going on - without controlling other people's characters *or* any more of the outcome of an RPG (all that's set in stone in Holocaust is that Ken'atra will
get the Time Matrix. And we agreed on that before the RPG started, in fact told a little of how it happened near the end of Cantina 6, while purposely leaving it vague.)
Sorry about this Keiran