https://www.techradar.com/news/htc-vive-trackers-get-a-2018-update-now-on-sale

HTC surprised us yesterday with their announcement of the HTC Vive Pro. Now they’ve quietly dropped another surprise product into their store: updated Vive Trackers. 

HTC team member Shen Ye confirmed on Twitter that his company had, without an announcement, updated their store page to sell the 2018 model of the Vive Tracker. The 2017 model is no longer available for sale.