... were Venus and Jupiter in a conjunction like the one this year 2017 years ago, and is it the case that we've not had a conjunction like it since?
Yes and No, respectively
TLDR: Venus and Jupiter passed in front of one and other in 2 bc and have since done so, but will not do so again until 2065.
Let's get a couple definitions out of the way...
A conjunction is an event when two or more astronomical bodies appear close to one another in the sky.
Occasionally they will pass so close to one another that the Moon passes in front of one of the planets; this is called an occultation.
The planets form conjunctions with one another more rarely since they move across the sky more slowly. However, striking planetary alignments typically occur every few years.
As the page you linked : The Frequency of Striking Conjunctions of Venus and Jupiter
goes into, the significance is due to how closely they pass. Well, we can do one better, necessarily if they occult, then they must, at some point been the same as this one (and even better). So when was the last Venus-Jupiter Occultation?
Planet-on-Planet Occultations (Worldwide)
Venus-Jupiter: Last 3 Jan 1818 Next: 22 Nov 2065, 14 Sep 2123, 8 Oct 2335, 12 Feb 2912, 8 Nov 2954, 13 Aug 2986
So there was a closer conjunction in 1818.
This page Venus and Jupiter Occultations agrees
1818 3 Jan 21:51 UT 16oW 10",30",12" Occurred over Far East No History Record
but also lists a few going back, including ...
2 BC 17 Jun 17:53 UT 45oW 26",32",28" Very Large Elongation Occurs over Middle East
The next one seems to be in 2065. But it will apparently happen near the sun so won't be possible to see.