Not really. Conductors provide the interpretation, as well as being a far more efficient way to rehearse and prepare. Orchestral players still have to play at different times for the music to come out in time at the front. If you've ever listened to a large orchestra from behind you will have found the timing is all over the place, as the back row is playing ahead of the front row. And this can all cause a delay behind the baton of a second or more, which is one of the fun things a conductor has to deal with.
In days when radio studios had tape decks and then chip delays, sometimes they got inserted in an announcer's headphone feed. The first time, even a tenth-second delay will make most persons stutter to a stall. With experience you learn to just speak your piece and ignore the echo. There is very little real improvisation in most public performances. The player just makes the plucks which his/her muscle memory knows will make the desired sounds. There may be some awareness of pitch errors ("hmmm, D is always flat") but guitarists usually trust their frets and their guitar technician/tuner.
I've heard this before. But how on earth do they learn to do that? How do you learn to produce a sound that's right far away in front of you, at the expense of a bad sound where your ears are?
Or is it simply a case of the players near the front of the stage listening to the sounds from the rear of the stage, and playing in time with them as the sounds reach their ears?
The combined sound would continue to propagate forwards, and each row of musicians further forward would simply play along with the sounds they hear from behind them.
This would make each player play a little further behind in time, the closer she was to the front of the stage. By the time the sound leaves the stage, it would all be in time.
But it would all fall apart if musicians at the rear of the stage listened to musicians at the front, instead of the other way around.
And there's the problem of left of stage / right of stage synchronization. How is that managed?
-Gnobuddy
From what i've seen: by playing together regularly (by sections of course but rehearsal with the whole orchestra too) and... being some kind of virtuoso ( this is the case of even the worst players in 'big' orchestras).
Practice, but they don't know they're doing it, of course. Large groups acquire their own inner momentum. It's quite an occult process.