Are you sure?
As far as I know, this is the sequence of events
- players who didn't have magic buildings but did get Blueprints wanted another use for them
Am I wrong in my understanding?
Yes, I'm sure, and yes, you're wrong in your understanding, because no, you haven't got the timeline correct. You're basing your understanding on an incomplete sequence of events., which completely ignores the first half of the process.
- Players spend a year+ saying the event buildings are beautiful and they wish they didn't have to discard them. (At least partly misleading, on at least part of the player-base, because for a lot of people it was their power, not their beauty, which they wanted to preserve)
- Players suggest repeatedly that a way to upgrade event buildings would be nice.
- Developers say they are going to make upgrading event buildings a thing
- Developers say they need to adjust the power of event buildings because they will be upgradable soon
- Developers adjust power level of event buildings, leaving some people in chapters 4-6 with up to -10,000 population (half of their total population) (estimate, personally, I only experienced -7,000 population on my Dwarf era city which I abandoned.)
- Developers say, we'll give you a free magic residence to make things better, and a free event building when we figure out how to make that work.
- Blueprints come out for people who get 10 chests in a tournament, allowing them to upgrade magic buildings.
- Players say this isn't what we asked for.
- Your timeline begins
So basically, your timeline includes everything that makes players look bad, and nothing that shows the developers failing to live up to what they indicated they were planning. Other than that, it's an excellent timeline.