Maybe PtG wont receive the refit with 80 silos but stick to the 20 he has already, fitted with Mega-Tsirkons.
Sounds good but the only thing you could achieve would be longer flight range with a scramjet powered missile... I rather doubt a 7 ton missile the size of Granit could be made to fly faster than Mach 10 or so, which means rather than flying faster than Zircon it would just fly a lot further.
It wont be any harder to intercept of course, so although the idea of applying new technology to old missiles to massively improve their performance sounds interesting, in practise 80 UKSK launch tubes that can fire a variety of missile types including anti sub and anti ship and land attack missiles just makes more sense than trying to raise the dead.
Vulkan and Granit were very good missiles for their time but essentially the new Zircon is half the weight, double the range and about 5 times faster... what is not to like... loading 20 in the new UKSK launch tubes and you have 60 free tubes for land attack or anti sub missiles, not to mention a range of other new things they are working on like four Redut missiles or Shtil missiles or EW rockets or even Packet-EM anti torpedo rockets....