January 19th, Riot Lyte said "a few weeks after the season start" (https://www.reddit.com/r/leagueoflegends/comments/41njpt/the_2016_ranked_season_updates_on_dynamic_ranked/)
February 4th, Riot Lyte updates it to "a month or two" (https://www.reddit.com/r/leagueoflegends/comments/443wxg/riot_lytes_update_on_solo_queue/)
March 3rd, a Tweet from @RiotSupport said it was "a month and a half" away (https://www.reddit.com/r/leagueoflegends/comments/48ydr1/solo_queue_confirmed_notscrapped_supposedly_1_12/)
March 22nd from Riot Socrates, it became "...we're concerned about the impact solo queue will have on matchmaking as a whole, and we’re assessing how to best proceed. Once we've fixed match times and position selection, we’ll have a better update on other queues." (https://www.reddit.com/r/leagueoflegends/comments/4bil21/new_champ_select_update/)
And in a reply to that March 22nd post Riot Socrates confirmed (emphasis mine): "We'll be honest: there's definitely a world in which solo queue doesn't return, but we'd rather keep it on the table as we work through these issues before making a final decision." (http://boards.na.leagueoflegends.com/en/c/riot-official/6WuZKauE-new-champ-select-update?comment=0037)
Yesterday, Riot Korea held a "Bush Talk" on Youtube.
Riot Korea Runetera has confirmed that solo queue is on hold for now.
To translate what he had said:
5번째로 솔랭 출시여부 (5th question, in regards to solo queue release)
이거 일단 좀 괴로운데.. 거짓말쟁이가 되서 개인적으로 좀 슬픕니다만. (This is a very painful subject because I feel like I have lied to summoners so I am pretty sad about the situation)
2월말까지는 솔랭에대한 업데이트가있었습니다. 처음에는 몇주걸릴꺼다가, 3월말쯤에 말이 바뀌었습니다. (Up until end of February, we received updates about Solo queue - at first we were informed that it will take few weeks for Solo Queue to come out, however at the end of March, things have changed)
일단은 잠정 중단되는걸로 알고있고 그뒤 업데이트는 없습니다. (For now, Solo queue development/launch is on hold and we have not received any update in that matter.)
Hope you can learn to like Dynamic Queue because it's all you're going to get. But don't worry. URF is coming! Play URF. Enjoy URF. Do not pay attention to Solo Queue being scrapped completely. Do not pay attention to the man behind the curtain. Riot is going full Blizzard and Jagex here, doing what they want. The failure for Solo Queue to return will end up killing this game in the long term.