I dont think it will happen this season,the 2 top teams in the champions play offs will be promoted to make a 14 team SL.

Doubt they'll change the format just ten weeks from the end of the current season.

Where's this from?

The competition will definitely run its course in the agreed format.

If the RFL do not like the eventual outcome, they do have the power to change it. However, the current format will definitely go ahead.

Although it could make sense to promote 2 sides from the Championship, this would necessitate a change in format, as it would leave 2 teams without end of season fixtures and a drop in revenue.
The current structure has many faults, not least that it makes it very difficult for the bottom half of SL to grow as they are permanently under threat of relegation and whilst 1 up 1 down doesnt totally remove the threat, it does in theory put less sides in jeopardy.