The recent letter concerning the university letter for a teacher's license is not new. It is being reinforced. When I came to Thailand in 2005 I was working in another country and was told by my headmaster to get a letter for my own records in case I lost my transcripts etc...for verification
I went to see my family in the US and luckily I got my transcripts and letter of graduation verification to go with my degree certificate. When I got to Thailand I had one bag stolen. It was a laptop case that I used to carry my papers in (no laptop). In it was my letter and transcripts but not my degrees which I kept with my passport.
Long story short. At my first job to get a permit to teach and not a license I was asked for a letter from the university. I emailed them and told them where I was and the address of the school. In two weeks I received my letter and went to the permit office and it took 30 minutes. I had a permit.
In 2010, I got my teacher's license and all it took was my school sending in the letter and my BS Ed degree. It took 2 months total. I have now renewed my license again and all is well.
So for you that worry, don't! Just email your university to send your letter to the school you are at or wherever and it should take about two weeks. I didn't have to pay a fee for it even though they sent the transcripts and the post fee. If you are a registered teacher your information is online at the country or state licensed teachers section in the Dept. of Education section website. Easy stuff so don't worry. It is just how things work.