There is not just an external audience.
The reveal of Pukguksong-1 and later Pukguksong-2 upped the ante. Solid fueled rockets always do.One analysis
says that they might be based on RT-15M 1st and second stages respectively.Other analysis
by 38north came to other, larger diameters, so RT-15M would not be a fit.
Having access to solid fueled Sowjet SLBM plans is a big deal, even if they were never fully developed.
The tracked TEL looks somewhat like the RT-15 (SS-14), biggest difference is that the original was hot launched. [link
If Norberts size analysis checks out the chance that NK actually has something for their large ICBM canisters rises drastically. SS-13 clone anyone? - Not that they have some, that it looks like they want them to look that way...