Gordon Shumway said 
As to adding notes at the start and end, that's just to complete a rhythmic sequence for beginners, I assume, so that they don't lose the beat or their place. I never did that on piano. (other reasons might be to fix the intonation in your ear, but after a while that should be unneccesary too) 

Just found this Bushkova video which mentions the subject: -

I find it a little bit disconcerting the way some professionals make no attempt to sound like competent violinists when playing in these instructional videos (lol).

Incidentally, I haven't watched this video all the way through. What I have seen doesn't agree with my favourite fingering system as decribed in your 3 octave A major thread (and there's another video on the three octave G scale where the amateur violinist slides down to their 4th finger on the G string. It sounds terrible). Unfortunately this thread is now clashing with that one . Maybe the mod could group all threads on scales and arpeggios together?