Northern Design Bureau hasn't got a contract yet apparently https://flotprom.ru/2018/%D0%9E%D1%81%D0%BA20/
"The SSBB carried out certain pre-design works in accordance with the wishes of the Russian Navy, including by initiative, but now the bureau expects the contract,"
Sure will be interesting what they go with for the M version:
Minimium end would be something like just sticking Pantsir-Ms instead of Palma. (and associated 4 array radar a-la 3rd 22800 instead of the Pozitiv)
Top end could be some behemoth like the model from whatever military show it was.
I'm inclined to something more inbetween, a small stretch, Pantsir-M, taller mast, 48 Redut cells, 24 UKSK cells. (or 64* UKSK-M?)
Someone at Balancer even suggested there might even be only small or no weapon increase, apparently Gorshkov
is packed super tight to fit the capabilities it has, making a bigger ship might just be used to space things out a bit, improve living quarters, increase range etc.