My understanding of the "Emails Sent About Plot Sizing" thread is the same as Mysk's. Note however that I'm not a developer, so take this as a personal opinion, not something enhanced by the Emissary tag.
I think I'd also add the following:
f) If one of the small plots is retained for fear of losing it, but all the space around it is opened up, then *perhaps* that small plot can be expanded into a removed small plot beside it.
g) If retained small plots are landlocked by larger plots that they don't want to change, or by other retained small plots, I'm pretty sure (f) won't occur and you'll be left with the small plot.
h) Keep in mind that changes can only be made if the plots getting removed are owned by the community on Blight, Chaos, AND Order.