The new rumor that they are working on Brewster now and are not sure when it will be done makes me wonder if Brewster was actually in the plans from the beginning or if they only decided to add him because of the outcry and/or popularity of the game. I've started to lean more toward the belief they didn't have many plans for updates after year 1 and are sort of making it up as they go along now.
It's worth noting, in Ninji's initial datamines of v1.0.0 he found
*
Redd would dock a boat at the north beach and sell real/fake art - Ended up being true
* Museum would upgrade to include art - Ended up being true.
* Possible evidence of a museum shop, and the
museum cafe - NOT YET TRUE (Museum Cafe is looking more and more possible)
* Shrubs - Ended up being true
* Vegetables ( tomato, wheat, sugar cane, potato, carrot,
pumpkin ) - Somewhat true, we got pumpkins
* Deep see creatures - Ended up being true
* Diving to get said sea creatures - Ended up being true
* 3rd Nook's Cranny upgrade - Not yet true (could have been our current shop with RS tent being the 1st)
If I recall correctly though, versions in-between v1.0 and v1.10 had removed code reference to the Café. So it's possible Nintendo scrapped the idea, and brought it back due to complaints, or Ninji's datamine had made Nintendo more cautious over leaving spoilers in the code.