Certainly, it's anyone's individual choice to get the lifetime update deal or not.
In my case, I have not made a Sonar purchase in about 2.5 years - X3. I got into the lifetime deal for $199. If I had paid that $99/year sub for the past two years, that's how much I would have spent. I HAVE now seen what the subscription would bring during those two years. As long as I see that as worth the $199 it was for my lifetime sub, even if they never did another thing, I still got what I wanted, knowing what I was getting, and paid the same amount as I would have anyway (in the period where I didn't know what was coming).
So I look at it as anything they add from today forward, for me, is completely free.
Meanwhile, if you want to keep paying the $99/year, good luck, I hope it works out for both of us. Either way, Cakewalk gets that money from both of us for the next two years (if you spread my lifetime payment over that period). What they do with it remains to be seen. If they do what's on the current rolling pipeline plus some other things they haven't announced, great!
Folks - it's really not that hard! If it's a money grab, there's a business reason for it and if you think every dime you've given Cakewalk over the years wasn't to fuel a business, you are simply naïve. If it's not a money grab and they are just looking to retain loyalty and are bringing people back into the fold that used to be very active (like me), then "thanks Cakewalk, you brought me back".
Enjoy your music making, whether you do it with your current version of Sonar and never update again, subscribe to the monthly, yearly, or lifetime model, or switch to another DAW that pleases you at the moment and inspires you to "do your thing"!