With a March launch period which means the 3GB memory IC is already in hand because there's no way the laptop manufacturers would be able to hit that otherwise.
If the date is to believed and March is the end of the Q1. Samsung has not released it's 24Gb chips public yet, though they have said they plan to announce them in Febuary.
Samsung To Showcase Their 42.5 Gbps Super-Fast 24GB GDDR7 Memory At ISSCC 2025
Samsung will showcase its 24 GB GDDR7 module at at ISSCC that can run at a whopping 42.5 Gbps of speed.
wccftech.com
The 50xx series has already launched. Unless you have a handy time machine that lets you get a supply from the future then send them to nVidia in the past, don't expect to them them until mid cycle refresh. Now AMD hasn't yet announced it's next set, and it could very well be because they delayed them to use the newer memory, who knows.