Almost. You can apply your chosen transition to all clips on a single track but you'll have to repeat the process for each track.
Click on any track or clip to start, then go to the Transition Room (
F8) and click on this button that appears above the timeline. You'll then need to choose the style:
To get the "apply to all" button to reappear after using it, select a new track then change to a new room, like FX (
F4), then click back on the Transition Room.
It's not as simple as "all clips on all tracks" but it should still be quicker than applying transitions manually to all clips.
You can also use the button shown in the Help
file, which is located next to the
Search the library box at the top of the Transition Room.
Note that while the instructions state that "you can add transitions to all the video, image, and effect clips on the timeline at once" it actually only occurs on the selected track.