Changes in the Weather
So, back when weather first came out, with Hoenn, it had pretty profound effects on spawns. Some mon essentially only showed in some weather (Lotad, Cacnea) and WB spawns might drown out everything. A minor tweak here or there, and some balance was restored between WB and biome. Lotads and Cacneas still showed.
And then they announced a further reduction in weatherboost effect on spawns, back around when Sinnoh first dropped(?). I don't know about you but it changed spawns dramatically. Uncommon spawns reduced noticeably, and most spawns were either event, regional, or Rat-class common. I hadn't seen a Lotad since at least August before Sunday and then I got 4.
Now, with their overhaul last week, it seems they've shifted back to about how they were in January. Weather boosted spawns were everywhere the last few days, and they're still spawning nicely in and among the Zodiac event.
Are you seeing similar shifts in spawn patterns in your area?
Answers
This has been an active point of discussion on TSR for some time now but yeah, whatever they did to weather spawns around Sinnoh's release effectively killed them. Cacnea, Lotad, and Snorunt went from being common in their respective weathers to nowhere to be found. Castform had also become scarce at this time, however I've noticed them appearing much more regularly since the Hoenn event.