I'd argue that things have, over time, changed subtly and from a point of view, drastically. However, that is rather a matter of perspective. Change is slow on the server, and I've got a few arguments as to why that might be the case - and also why it should remain the case.
Firstly, the change that has taken place has been gradual, but it has happened nevertheless. Drastic change tends to be immediate, and sudden. A great disaster or some such. However, player agency driven change tends to be much slower, out of necessity. If it was not, we would end up with a violently different setting rather quickly, that would lose that fundamental element of what makes it what it 'is'. It might be fun for me for example to create an order of Ilmatari knights running around, but its not Ravenloft. It won't happen, it should not happen, and I hope that it never does. It does not fit, and would upset the balance of the setting considerably.
Change that takes place needs to be gradual because it shows then that the player is dedicated and that they can do it without relying solely on a DM to facilitate it. But change, as long as it is conducive to the setting, 'can' take place. But it must, and I emphasise this, be conducive to the setting, fit with the established setting, and involve other players. For an example to this I'd point to the highly successful Company of the Fox, which by this point is an official faction in all but name. It is a very drastic change from the establishment, but it fits.
There was the second Falkovnian war as well, which led to the creation of the Fox. There was a great deal of society upheaval, and change, and indeed a lot of it went back to the way it was. There was also Lyssa's reign in Barovia, a drastic change that had all manner of conflict that eventually changed back by dint of player agency to return Strahd to power. Both of these events were drastic changes, but both of them left the setting familiar to both newcomers and the establihshment, and both of them were conducive to the setting.
From personal perspective, I know of a canon NPC that met their final end recently as a result of a very long story culminating to an ending. That was a 'drastic change' that nevertheless kept the setting running smoothly. Another canon NPC was foiled in returning into being a presence on the server a while back as well, and that was in fact the prevention of a major change.
The argument could be made that the setting is too static, and a lot of people make that argument from what I understand. But there are two reasons why it should remain thus. Firstly, it keeps the setting familiar and keeps players familiar. I've been on servers that deviated heavily from the canon due to IC events and the alienation from what was known was altogether palpable and made the setting too difficult to get started in unless you were 'someone in the know' already. The second reason is tied into the Dark Lords and the Dark Powers. The domains of Ravenloft are not made for the players, they are made for the Dark Lords, as their prisons. As such, the Dark Powers make sure that the domains remain -very- static by manipulating events to make sure things remain the same, thus perpetuating the despair.
This is a difficult thing to wrap ones head around. As a player, and as a person playing with a bunch of pixels, the habit forms that we are the star of the show, and subconsciously or not that mentality is always present. But the setting of Ravenloft is about the Dark Lords. They're the stars of the show, 'our' job is to exist and survive while they do their dread machinations, to outwit them if possible, to survive and avoid their attentions. And because its about the Dark Lords, the Dark Powers themselves will ensure the domains remain as they wish it for those Dark Lords, to draw out the 'torture' as much as possible. This can change, and has changed - Soth, for example. But change, if it comes, will come slowly. We are now in 5th edition, and no new lore about the setting has come out in a long time, for 3.5. As no new lore has appeared changes haven't taken place to suit that new lore. It leaves us a bit stuck, but it is what it is. Nevertheless, change 'does' happen, as noted above. It is just slow and steady, at least for now. I admit I tend to prefer it that way myself, gradual change is much more realistic than sudden and haphazard change.