A lot of thoughts-
1. I think Expeditions worked because it was new- doing it every set is going to burn people out like crazy
2. If people continue to eat them up, it's going to lead to Standard being super cheap because of price depression. This is good for standard players, but bad in a sense that the cards will have no value, and thus selling out or trading into modern/EDH will be impossible
3. This seems like way too much- 20 is probably the right number per set. 30 in large sets and 25 in small sets makes it too hard for even hardcore collectors
4. This reeks of 90s Sports Cards gimmicks, which, even if Magic is fine (as they keep saying), makes me more worried about the future of the game than anything they have done since the invention of Mythic Rares
5. It was fine to do with lands, but playing around extra cards in limited will not be fun, especially when we get a cycle of spells like Bonfire down the line.
Overall- This is a bad thing. Combined with all the shit they have been announcing recently, I'm worried about the future of the game.