I haven't seen this news anywhere else, but yesterday I used the MRT and when I tried to pay at the ticket office to get my 50pc discounted ticket for being elderly, I was told it was free, and will be free for the Songkran holiday period. The lady said (in Thai) it was free for either 3 days or maybe the next three days. I think it is just for the over 60's. I have never been asked to prove my age (I am 69). I just specify my destination and say ' khon chara' or 'phu chara' and Bob's your Uncle.
Sorry for posting a bit late but there is still tomorrow.