It is possible to pass through them for near-instantaneous travel, with the correct technology.
Overall you can expect the game-play to have been slowed down a little, and you now need to make active decisions on which star systems you want to expand into and control. Stellaris has changed quite dramatically for 2.0, and in our experience, for the better.
The patch was released alongside the Apocalypse expansion pack. Patch 2.0, aka “Cherryh”, was released on with the checksum daf0.