Judging by documentation, it looks plausible, but the related functions (animcurve_channel_new, etc.) are perhaps among the least-used in GML so it’s hard to tell whether
Updating a curve this way will correctly reflect changes across various ways to use it (like in sequences)
Whether there will be more than a few people using the feature (it’s been almost 3 years since animation curves were introduced and I think you’re the first to ask this)
I personally use animation curves a lot for giving juice to the games and being able to tweak the nodes of the animcurves on runtime would be a quality of life improvement. So if in the future there is any update on this side would be very welcomed by me jajajajaja
