A "hefty" agility nerf which still puts it on top of the VHF agility list (Yes, there are a couple of VHFs slightly faster than the Eagle, but those are exceptions and are not considered "standard" case ships for obvious reasons). A papership with insane agility but considerably large hitbox (i.e. an ultimate "duel ship") despite not being technically broken balance-wise, is too specialized to fill the role of the "generic open to all all-arounder ship", which is why the stats on Eagle was adjusted to make it an actual generic fighter which can be used with every style and in every situation, while not being the "best" in any of the fields. So it's not really as much of a "nerf" as it's a "repurpose".
On the subject of the Sabre, nothing other than the powercore was touched for 87. Sabre has been overnerfed over and over with every mod version mainly due to its unusual hitbox full of holes and its forward firepower (And the broken strafing, needless to say). The late balance team was tryin to solve the issue by hammering its agility, but that was not the actual issue with the ship. Now that its forward firepower is somewhat adjusted with its new core, it can actually undergo a review and be rebalanced like a standard ship, without having to worry much about moving back toward the old sweet 85 Sabre.
So let's just put it this way - The current balance team no longer follows the "Don't fix what's been broken for too long" policy.