Thank you!!
The problem with timelines are something we're aware of and will try to fix in later updates, to keep everything immersive. Sombra will be the first one to get those for sure.
In regard of losing progress, that shouldn't happen, since saves are transferred automatically in between updates. You just need to install new build, and all your saves will already be there. Also, in the worst case scenario, you can always skip to new content when starting new game, which will unlock everything, but the content of the latest update. This feature is there in case you actually lost your progress for some reason, though we're doing our best to make sure it doesn't happen.