HI've already finished my MA TESOL Pre-service at UCL Institute of Education and am still waiting for the result this November. My professional teaching practice was less than 2 years (in fact, I went to be a part-time lecturer straight after my bachelor graduation and lasted for 6 months). However, my nonformal English teaching experience (including volunteering activities) was much longer than that.
The were 2 TESOL programmes at UCL, first is the programme for the experienced teachers (>2 years of teaching experience), while my programme is for the less experienced teachers, considering my professional teaching practice.
My MA concerns on theory and research, not on teaching and practice to quote @twos1c, and although this is a new programme (I was in the 2nd cohort), some of my friends there are planning to do their PhD as well.
As a background info, I got GPA 3.42 from and Indonesian university and I wrote a strong personal statement, also I was a sponsored student from Indonesian government. Hope this helps and all the best!