Other merges will be possible the season after the next one at the earliest
Merges plural. Two? Three? Where might they be? What size countries are we talking about? The largest country to be merged so far is South Africa with less than 16 managers. Is that the limit or is it higher? For example would Japan and New Zealand be candidates for a merge? Will there be one merge for Asian countries or two since it's a very large continent? I could think of a plethora of other questions that should be answered but since I don't expect an answer I'll leave it at just these.
These are just some of the variables that need to be decided upon for every possible merge. Yes, there are several planned as we need to group countries by many parameters, the most important being similar game start time (geographic closeness).