Escape on BFR will likely be similar to escape with Falcon 9/Crew Dragon: that is, BFS itself has more than enough thrust to very quickly distance itself from a failing BFB, and it would probably be able to land itself on a nearby but safely distant emergency landing pad.

Now an argument can be made that BFS needs an escape pod or two, but those would mostly be useful in circumstances other than failure during launch.

(For those unfamiliar, BFB = Big Falcon Booster, BFS = Big Falcon Ship. BFR is both working in unison)

The escape system used here and on a previous Soyuz abort in 1975 didn't use the LES, it used the Soyuz spacecraft's own engines, a very similar abort mode to what the BFR would use.

The rocket doesn't need one. The spaceship does. But considering that the whole thing gets redesigned every two months I wouldn't worry too much. It's still years from flying, so plenty of time to change stuff.