How old is this scope?
It looks like the ADC is obsolete and every modern FPGA supports at least DDR3 SDRAMs. I was really surprised to see SDRAMs as acquisition memory.
The scope itself is only a year old, but the design likely dates back several product generations.
The WaveJet 300 Series is pretty old, it was introduced by LeCroy at the end of 2006.
There actually are three iterations of this scope: the original WaveJet 300 (white case, 2006-2008), the WaveJet 300A (black case, made from 2008 to 2014), and the "new" WaveJet 300T shown in the video which came out last year and is a essentially 300A with touchscreen.
They seem to make a lot of use of 45 degree (and some, arbitrary) angle component placements. Not something you see a lot of these days.
As for giving Iwatsu all the design cred, I'm not to sure. Ive pulled apart a lot of old real lecroys and they all make use of those shielding bars between front end inputs. In fact, just from the look of the general circuit topology, the design is very reminiscent of most 9384 series lecroy motherboards
The similarity with older LeCroy scopes is no surprise since the WaveJet is another result of LeCroy's cooperation with Iwatsu which started the '90s when LeCroy rebadged Iwatsu analog scopes. Later when LeCroy was looking for a manufacturer for its new WaveRunner LT lower high-end scopes they increased the cooperation which included quite a bit of knowledge transfer about hardware design to Iwatsu, although most of the scope was designed by LeCroy. The WaveRunner LT was a success and so the cooperation continued for the WaveRunner2 LT (lower high-end) and the WavePro 900 (upper high-end), again mostly LeCroy designs. Sales were also divided, with Iwatsu selling the scopes under their name in Japan, and LeCroy selling them under their label on the rest of the world.
At the same time (end of the '90s), LeCroy also bought in a small Iwatsu-designed portable entry-level DSO with b/w LCD and resold it under the LeCroy brand as LiteRunner LP. However, being made in Japan it was pretty expensive, especially for its price segment, and it didn't sell very well. In the end it was cancelled around 2001/2002 if I remember right.
Three years on LeCroy again wanted to gain a foothold in the entry level, and so again teamed up with Iwatsu to come up with a new entry level scope, which was the WaveJet 300. However, like with the LiteRunner LP, LeCroy wanted to buy the scope ready to sell, so again this was a Iwatsu design (where they used the know-how they learned from LeCroy). When the WaveJet came out it had good specs, but as with the LiteRunner the problem was that manufacturing in Japan made the scope pretty expensive, and although the Dollar/Yen ratio isn't as bad as it used to be the problem with the WaveJet's price remained. For the Iwatsu-labeled counterpart this didn't matter much as Iwatsu was mostly aiming for the Japanese market only anyways.
The price was the main reason why LeCroy later teamed up with Siglent for a new entry level scope that was to be cheaper than the WaveJet, but the first models (sold as WaveAce 100/200) were awful, plagued by ridiculous firmware problems that Siglent couldn't fix in a timely manner, so the WaveJet remained. The successors WaveAce 1000/2000 were better, but not by much, which is why the WaveJet remained on offer, and subsequently even got a facelift (WJ300T) which includes a touchscreen and a few other improvements (a similar thing Keysight did with the DSOX30000T).
Today it's specs are outdated, but the WaveJet is still a very good and also very reliable scope, even though the UI is typical Iwatsu which means it's not the most intuitive or logical, and a bit old-fashioned.