Believe it or not (waves to
@Herodite!), I'm
still undertaking an increasingly slow and laborious 2-3-daily in-depth review of my own Neighbourhood, so that when (in fact, it's rapidly becoming 'if'...) I gather the energy to collate all the raw data into a form concise enough to post on this Forum, I will at least have what I consider to be reliable data to present, rather than even educated or informed guesswork.
As I say, this is taking forever (an hour and half per 2-3 days), and involves manually visiting every City in my discovered range (to determine its alive/dead/progression status), and typing the results into what is becoming a monstrously large text document. But just for now, I can at least confidently state the following, based upon close observation since the 'Big Move' of last November... assuming that this has even finished, that is...!
1. There is no real difference between Mondays or any other days when it comes to the moving around (out or in) of Cities near me. Moves occur every day - sometimes one or two, sometimes two dozen or so, and everything in between. There is also no easily discernible pattern when it comes to which hex spaces are changed; some hexes have had the same live or dead City for months, some have been Gold Mines for months, some alternate between live/dead Cities and Gold Mines... and so on. There is, however, a slow but steady increase in what appear to be permanent Gold Mines to the North and East of my own City, and it only becomes clearer, as time passes, that I have been left on the edge of the inhabited Map (I'm a daily active player in mid-Halflings), while most of my useful Trading partners were moved away, wholesale, during last November's 'Big Move'.
2. Cities of all sizes, both newly founded, still-alive, and/or already-dead, are frequently moved in and out of spots previously occupied by other Cities, although the sizes, types, and discovered Map areas of these Cities (the latter presumed by myself, and based upon the City's level of advancement) are all liable to change from move to move - there is no pattern, for example, of either start-up or Guest Race-level Cities replacing others, or being replaced by others, of similar advancement levels (they probably DO have the same Boosts, though, since many already-dead Cities which move into any given have the same types of T1-T3 Manufactories built - and/or are Scrolls-Boosted).
3. Even isolated/scattered Gold Mines are more often left as Gold Mines than filled by moved Cities (alive or dead). This is not including the large and growing area of near-permanent contiguous Gold Mines now developing to the North and East of my territory - as already mentioned in point 1.
4. Small live Cities are frequently moved away after only a couple of days, whereas larger Cities (alive or dead) persist for much longer.
5. Small dead Cities can persist for many weeks or months, even those which have been abandoned at the start of the Tutorial (one House/Workshop). This applies both to abandoned Cities which started up near me in the past few months
and moved-in already-dead small Cities.
I could go on, but then all my data-gathering would be in vain, and I'd also stray into making statements which I can less well support, at the moment.
Still, if this is 'working as intended', then I can only suggest that what is intended does not work very well, to put it politely... and speaking as a player who was left on what is now clearly becoming the edge of the inhabited Map, while almost all of my useful Trading partners were moved away.
I'll try to find the enthusiasm to collate and post my conclusions in full at some point, but to be honest, I don't think it will do any good. Hey ho.