This is really mostly a big announcement for Cakewalk, not so much for me as a Platinum member. As much as I appreciate no longer having to pay additional money annually for upgrades, the cost of Sonar is small in comparison to the costs of instruments (VSTs, keyboards, etc.). I would, as crazy as it sounds, actually prefer to pay if it means that that Cakewalk has a sustainable business model. At this point, Cakewalk appears to have bet their future on new/recurring Artist and Pro members and the hopes for a new Mac business.
I does nicely align with the information that most new customers, at least for a while, were Artist, and so maybe the Platinum members are of no fiscal relevance to Cakewalk, but valuable for the community.