If this is indeed the end of Timeless, I'll be disappointed but not surprised. I'll also be satisfied with the way they ended it - open ended with a big reveal, but not with an actual cliffhanger. If gives the viewers a chance to be creative and imagine their own continuing story, if they wish.
I would love to have seen the show's "time travel bible" where they've set the logic for what they can and can't do, and what are the implications as multiple timelines appear. I thought I had it figured out at one point, but eventually realized a flaw in the paradigm I'd constructed that was inconsistent with what we'd seen. (The show itself was not 100% consistent either, but mine was a fatal flaw that couldn't be hidden under the rug.)
I said more than once on the IMDB forum that I'm pretty much convinced that it's not possible to create a time travel model which is interesting and coherent, and still produce a story that is watchable in an episodic format. Either things change "too much" to produce a story we can keep up with or care about, or things are too fixed to make their jumps of any consequence, or the paradigm is too complex to grasp, or some other possibility.
If the show does get cancelled, I hope Kripke will find a way to describe where they had been planning to go with it. A few years ago, I was one of the few who watched a show called "Defying Gravity". After the show wasn't renewed, the showrunner released a couple of online articles describing in pretty fine detail what the future of the story would have been. So this wouldn't be the first time.
And now we wait twelve weeks or so to learn about the future.