I received the pop-up message when I booted my computer this morning. The message popped up because I have Magix Connect operating. If you removed Magix Connect or disabled pop-up for Vegas, you won't get the message.
Interestingly, the previous pop-ups were offering an upgrade to Pro 16 Edit and Pro 16 plus a plugin for 149USD and 199USD respectively. The price has gone up, I guess, to cover version 17.
As you already have Vegas Pro 16, you should probably wait for the actual release of Vegas Pro 17 to upgrade, unless you want to purchase a second license for v.16 and get the license for v.17 as per this offer. There may or may not be (in a year or so) a similar "buy v.17 and get v.18 for free" offer if you'd rather wait. Disclaimer: I do not have any knowledge of future offers.
+1. Allways "caveat emptor." Everywhere, all the time. If you don't look after your own side of a deal, you will eventually come out on the losing end even with honest and reputable commercial partners.
That being said, I do think Magix could "dial down" the soft push marketing a bit. Some of the numbers are absurd.