You're supposed to be rewarded for good strategy. In a city building game, which this is, a flexible city design, that will allow you to exploit opportunities that arise, is a central element to any good strategy. You want to be rewarded with a "free" renovation kit, for not having been able to place these buildings. However, that's backwards; others should be rewarded for having been able to place them.
That's a hint for you, right there. The ability to upgrade buildings is meant to be rare. It's not news to Inno that Renovation Kits are most in demand when placing old event buildings, and it's no coincidence that they're rare.
You can do as I do. When there's an event building that you're sure you'll want for several ages ahead, target renovation kits so you'll be able to keep them updated. The good news is that, if you don't place the buildings immediately, you'll need fewer kits. The alternative is to only target the buildings, in all events, enabling you to regularly replace buildings from previous events.
You want to improve the benefits of the latter strategy, to where it includes the benefits of the first strategy.
No, it's not a "great feature for the game". It's a "feature" that would make the game easier for you, by lifting you out of the hole you've dug for yourself. There's a huge difference between those two things.
Making it certain that Inno won't save you out of that hole, is the fact that events are essential to their revenue. Anything that will make players less likely to take part in events, will hurt their bottom line. Players who neither need Renovation Kits, nor new event buildings, will be considerably less active in events.
They generally have annual repeats. Also, Inno is (or was; they may have decided one way or the other, by now) considering making the Cherry Garden available again, even before next spring.