The Jays' 2021 affiliates:
AAA (AAA East - NE, yes, you read that correctly)
Buffalo Bisons
https://www.milb.com/buffalo
AA (AA Northeast - NE)
New Hampshire Fisher Cats
https://www.milb.com/new-hampshire]
High-A (High-A West)
Vancouver Canadians
https://www.milb.com/vancouver
Low-A (Low-A Southeast - W, because there is a West division within the Southeast League because sure)
Dunedin Blue Jays
https://www.milb.com/dunedin
Every team will also have a single short-season club stateside, run by the clubs themselves rather than as affiliates (as has been the case with the rookie ball teams previous).
In practical terms, Vancouver has been promoted a couple rungs, Dunedin has been demoted, and the Lansing Lugnuts and Bluefield Blue Jays have ceased to be part of the Jays' organizational structure: Bluefield will now be part of a collegiate summer league, while Lansing is the new High-A affiliate of the Oakland A's.
I don't like the changes overall. By compressing the minor league structure, it's going to place considerably more pressure on kids to succeed out of the gate, while also making it far more difficult for low draft picks to get playing time. That's going to be particularly true in a year where you have a significant bottleneck created by COVID, where few 2020 draftees have gotten a real chance. But because teams recognized the benefits of having a metric tonne of minor league teams, MLB opted to level the playing field by screwing over those (including the Jays) who were willing to spend a little extra to support multiple short-season teams.
I am curious how the collegiate summer league works out. There has been an informal structure, the Cape Cod League, filling that need to some extend, but it suffered from drawbacks: the first being that it was expensive to enter, which created a barrier for kids that didn't come from well-off families.