Hunch. All seven plans in the record reached a paper eventually, but none of them had to do it while the councils being abolished were fighting an election, and Scotland's are.
The May market resolves on the same test with the window running to the end of 6 May 2027, the day of the Scottish council elections. The primary source is the bills list on parliament.scot together with the publications list on gov.scot; if neither can be read that day, reports by BBC Scotland and The Herald settle it.
We looked for times when a UK government announced a plan to cut the number of councils before any consultation or bill carried it, and counted the days until a formal paper appeared. We found seven. England, Wales and Scotland were all announced in the Commons on 21 March 1991, so those three count once. Two more come from the same Welsh reform programme. Five came before the Scottish Parliament, which now decides this. The closest cases come first. Two dates, June 1991 and July 2014, are known only to the month, and we used the end of that month.