I wouldn't put too much thought into those tweets, as it's just kids having fun with recruiting process.
Fleming's list actually went up, as he released a "Top 6" through Twitter back in July
Initial Top 6 from July 2018: Ohio State, USC, Clemson, Georgia, Penn State and Virginia Tech
Top 10 from December 2018: Penn State, Alabama, Virginia Tech, Georgia, Michigan, USC, Clemson, LSU, Florida, and Ohio State
and to answer your question on when either are planning to commit...I know Fleming wants to take all 5 of his OV's throughout the spring and fall, so would guess not until at least next Fall/Winter.