That depends on your preferences. For example, having a camera better in terms of resolution than my L1020 is important - that's the only reason I'm not getting the Lumia 950XL. So, for you, if all the other features and specifications of the Lumia 950 XL are more important than the need for a high-resolution camera, then you can go for it.
By the way, the Lumia 950 XL camera is better in terms of speed, video capture, OIS than the Lumia 1020. But for me, I won't go below 41 MP in a phone as much as possible.
Bottom line is that new devices with new features will always be released. If what's available now suits what you want or what you're looking for, then go. Otherwise, we would be waiting forever looking forward to the next device with new features and specs.