Here's where I'm seeing some disconnects regarding whether Discovery was canceled.
First, the fact - it has absolutely been canceled. Per DigificWriter's own rebuttals, the show has reached what is in all likelihood a more premature conclusion than folks like Michelle Paradise had hoped. Given the cast's warmth through the years, I dare say the same may well apply to the actors as well.
The wrinkle emerges in how the network is behaving about all this. It does not change the truth - that Discovery has been canceled rather than ending per the collective decision-making of all parties - but it does change the temperature, if you will.
Think back to the way Enterprise ended. Yes, as has been noted upthread, they got more advance notice than Discovery's crew did in some ways. And yet, the tone of it, the magnitude of what it clearly meant for the franchise, the clearly negative gaze from the higher-ups toward the production itself for years before the axe fell - Enterprise's cancelation felt like one, full stop, with all the corporate brutality and disregard that comes part-and-parcel.
Meanwhile, Paramount is practically treating their plug-pulling as some moment of triumph. Whether it's genuine or manufactured - and frankly, who cares either way - the higher-ups in this case have routinely expressed nothing but positivity toward Discovery. That they've elected to host special events about the show ties in with their clear choice to pretend this is less of a cancelation and more of a mutual deal. Why do that? Where's the money in masquerade? I think it boils down to the difference in overarching thought process between the Enterprise cancelation and Discovery's; for Enterprise, there was no need to smile and act like Star Trek, the franchise, was going business-as-usual. For Discovery, there is value in the IP still, in the here and now, and they want to tout that.
So, is it ultimately just a song-and-dance? This whole goodwill tour toward Discovery? I don't know. Maybe folks on-high really do adore the show, but the financials spoke louder after five seasons. Whatever the case may be, a few livestreams and whatever else is on the horizon have the bonus of softening the blow to fans so they'll presumably stick around and see what else is on the network. Les Moonves didn't have much reason to care about Star Trek in 2005. Paramount+ likely still sees a future with these productions, so the cancelation temperature is far more comfortable.